Olds 307 7a heads Jul 15, 2024 · Find many great new & used options and get the best deals for Oldsmobile 307 cylinder head core #7A 1985-1990 rebuildable OEM at the best online prices at eBay! Free shipping for many products! Cylinder Head Studs, Chromoly, Black Oxide, Hex Head, Oldsmobile, 307, 350, 403, with Stock Heads, Set. May 1, 2008 · You have to use Olds heads on an Olds engine. Thread starter TURNA; Start date Jun 12 But you'd be better off if find set of the "5A" heads, found on 1980-85 307 engines. a 403 Olds has a bigger bore Besides having two types of lifters, the Oldsmobile 86 307 cubic inch motor has two types of heads and two types of engines. All in all, it's a lot of work for very little effect. (A5 intake was used with 7A heads) But whatever Jun 9, 2004 · Best tip of all if performance is what your after; pull it out and install a olds 350. The #8 heads have 79cc chambers, as opposed to the normal 60-64 cc chambers for earlier small block Olds heads. Got to NHRA. go to Olds for 1971 and you'll find that the factory blueprint spec for those heads is 60. 403's came with 83cc heads and 8. 73 open :? rear, it runs real hard. 00 Oct 24, 2007 · Yah, anything for performance is better than 7A 307 heads. Sep 23, 2011 · oldsmobile 350 out of the 72should have 7a heads on itthink that motor with that head combo puts out 250hp and 350tp in stock form Toggle signature 83 Cutlass olds 350 swap stock manifolds welded to run duals with flowmaster 40 series muffles, stock turbo 350 transmission, 105 amp alternator Jul 10, 2023 · 1987 307 7A Heads Page 1 of 2 [ 22 posts ] Go to page 1, 2 Next: Previous topic | Next topic: Author Message; 442WMachines: Post subject: 1987 307 7A Heads. In Mid-85, GM changed over to a 307 with 7A cylinder heads and a hydraulic roller-lifter drivetrain. That means that the heads (and likely the whole motor) are 73-76 smoggers. It was used in cars from every GM brand (Buick, Cadillac, Chevrolet, Oldsmobile, and Pontiac). 330 heads are questionable heads to fit a 307 but are a good head. Nov 6, 2011 · Used on the regular hydralic lifters engines. Dec 5, 2009 · Those diesel manifolds look no different than any other small block Olds manifolds. Apr 29, 2003 · The bigger question is, why bother? The combustion chamber sizes are comparable between the 330 and 307 heads. Later 307's also used a thicker pushrod; I don't know the years. I understand from another BBS that the 85-90 307's with A5 intakes and 7A heads have the same port sizes as the 260's but from yet another I have been told that the ports won't match up. Sep 27, 2006 · The 307 heads have inlet ports that are 1. The heads should have the casting number on the top of one of the exhaust ports. Click on a picture for a larger version! Apr 28, 2012 · I don't have the casting numbers. 8 heads in 1973. The heads that were used are 5a, and I suspect they are from a 1984 or earlier 307. 875". These lifters are of 0. $300. A total of four basic Oldsmobile 307 engines were installed in Oldsmobile G-bodies. Add an answer. You need an A5 intake from a 7A headed 307 85-90 VINY or 86-90 VIN9. The chambers got big starting with the No. Jan 14, 2016 · The 307 is a great durable motor, adequate for it's time. I've been told to put early heads (68-72) on it mainly 1972 #7a heads from a 350 were the best but i really cant find any anywhere i was wondering if there was there any possible way to get good performance (350-400hp) out of the #4a heads that came stock Conversion Gasket Set, Oldsmobile, 260, 307, 350, 403, 455, V8, Set. Massive selection from top brands on eBay. Someone also hollowed out the cat. 045" (can't remember exactly). I am hoping I can get some help identifying exactly what motor this is, any and all details possible. That's it. Nov 19, 2023 · The 5A heads will bolt one without issue, have the nice, larger rectangular ports which will match up way better to your E-brock intake. May 21, 2006 · Item 4 is false -- the ports are small compared to the earlier generation sbo 307 heads (Olds 5A ports: 1. 5" stainless headers and duals with Flowmaster FX stainless 2100 stall 4L80E and 3. With the exception of the 68-69 D heads, all BBO heads have the same 80-ish CC chambers. I machined the seats and swapped out the valves to 1. the torque converter and trans valve body were the normal ones for the fwb, not the 442 ones (would provide an un-cadillac-like ride). com. The stock compression on your 86 307 is 7. Dec 25, 2009 · Its not worth it,trust me. And just to be clear, we're talking about the 7 A heads, not the 7A heads. The 5A heads seemed to appear for a while after '85 in the VIN 9 engine, but there are 7A headded VIN 9 engines too. Posted: Sat Sep 29, 2007 3:06 am do you think he/she would be looking in a thread named "307 heads"? valley olds wrote Roller-cam blocks, those with 7A heads, (some 1985's and all later 307's) use a larger diameter roller lifter (. Apr 14, 2008 · The 5A heads are most definately interchangeable. 99 read more; oldsmobile fabricated sheet metal valve covers 307,330,350,403,400,425,455 with breathers $ 259. Roller-cammed engines with 7A heads used the long-reach threaded FR3LS6 with gasket and I believe those too, were preset at 0. Install the 2. 99 read more; 69cc 403 oldsmobile complete aluminum heads $ 1,549. 472 cam in my 94 4X4 truck, with the low 4L60E first gear and a 3. 9 swap, auto and 3. The cast iron manifolds on my 84 307 are virtually identical and have the O2 sensor bung already in them. I would add a small cam like the factory Vin 9 307 performance cam if you swap intakes. What I'm asking is this; Is my idle problem a result of using 5a heads where originally the motor had 7a heads. 921"). MABBCO cylinder heads are cleaned, inspected, and machined on state of the art equipment. 562: exhaust valves. It was one of those”IIWII” situations, but I did flow one after the work. 11 posi, 28 spline axles, Moser Posi-Trac, true dual 3in with flowmaster 40's and dumps Triple Black. Want this question answered? Be notified when an answer is posted. 69 sq inches. Prof CrossWind Intake Manifold Chevy SBC 283 327 350 Fits Stock Heads 52025 (For: Oldsmobile) ARP RACE Cylinder Head 1/2" Bolts+Washers Oldsmobile/Olds 307 350 Dec 29, 2023 · I rarely get any Olds heads in the shop, but a couple of years ago I had some 7a heads from a 350 here. Sep 13, 2023 · 1987 307 7A Heads Page 1 of 2 [ 22 posts ] Go to page 1, 2 Next: Previous topic | Next topic: Author Message; 442WMachines: Post subject: 1987 307 7A Heads. 425,455 Oct 21, 2009 · You can easily machine any 350 heads for the larger 455 valves. 03 inches, the 5A heads were slightly larger than the 7A heads. Install stock Jun 10, 2005 · Up through Mid-85, 307's had normal 5A cylinder heads and normal hydraulic flat-tappet lifters. Aug 18, 2010 · 1985 for the VIN Y motors and 1986 for the VIN 9 (442) motors. You have a hydraulic roller cam in that engine so changing the cam is expensive. What I know: Olds 307 A4 intake manifold 7A heads roller lifters What else it came with: Dec 29, 2016 · Flat tappet cammed 307s used 5A heads. 307 Olds (soon to be 403 hopefully) 200r4, true dual straight pipe T-Top, 8. Great deals. The ports on the heads are barely large enough to stick your thumb in, and the compression won't support much cam duration. 000/1. Flat tappet motors got 5A heads, roller cam motors got 7A heads. Thanks! Ok so this is my first post but I have been reading everything I can. The 6A heads are kinda a mistery, they are found mostly on early 85 GM cars with 307s, the 7A and 6A share the same (A5) intake and the 6A heads also has the smaller swirl ports as the 7A heads. 307 Oldsmobile roller heads casting #0142/7A. Part Number: MIL-80247 Not Yet Reviewed The 5A heads were used on the '80-'84 "conventional" (non roller) 307. 86 442. So I was wondering about those claims of at least 20 hp just from the head swap alone. 307 "7A" heads. Jul 14, 2008 · There are lots of other Olds Vendors who you can trust: Dave Smith engineering :tup:: D!ck Miller Racing Inc :tup:: Rocket Racing :tup:: BTR :tup:: Regarding 307 Heads For a stock motor both the 5A and the 7A heads are fine Yes the 7A has tiny ports But this is just a 307 Its actually better not to swap heads on a 307 from a 7A to a Intake Manifold, Performer, Dual Plane, Aluminum, Natural, Square/Spread Bore, Oldsmobile, 307, 330, 350, 403. I used 5A heads with an SP2P intake on a stock 76 350 block with Corteco's and a,448/. All that made for about 200 horsepower,when driving it,it felt no different from a stock 307. 3" ports or 2. 62(both 45*), and blended the bowls to suit. Period. 5 to 8. Its worthless,so please dont waste you're money. Feb 5, 2014 · 85 Olds 442; 440 Olds ( bored/stroked Olds diesel 350 block ). The 72 head has a small capital "A" next to and a little below the 7. engines with 5A heads (casting #3317) Oldsmobile engines feature a 180° firing order to produce significant gains in mid range torque as well as upper RPM horsepower while maintaining excellent throttle response. The Olds 307 was produced from 1980 to 1990, and was Roller-cam blocks, those with 7A heads, (some 1985's and all later 307's) use a larger diameter roller lifter (. 1987 307 7A Heads Page 1 of 2 [ 22 posts ] Go to page 1, 2 Next: Previous topic | Next topic: Author Message; 442WMachines: Post subject: 1987 307 7A Heads. Remember that in 85 Oldsmobile went swirl port, and these heads are just plain restictive. Technical overview of the 307; Cleaning out the EGR passages; Differences between the 5A and 6A/7A heads; Differences between the Y and 9 engines; Modifying: 13-second 307 recipe Apr 23, 2013 · I recently put in a 307 out of a 84 442, has a reconditioned set of 7A heads, non CCC carburator and vacuum advance distributor. Cleaned up C heads, 9. The intake gasket sets are different. The valves used were just SBI stock replacements. 67 out of 5 stars Nov 23, 2018 · Will 80-84 307 (5A) heads fit an 86 (7A) engine ? I am pretty sure you can but I wait for the Olds experts. Remanufactured Feb 11, 2010 · All Olds heads will interchange. 1980 - 1984: "Y" motors, 5A heads, flat lifters, mild cam Jan 19, 2004 · You gain about 10 HP and you "must" swap the olds intake out as well. Your best bet is to find a set of #5, #6, #7, or #7A heads from 68-72 and have them machined for the W-31 size valves. , Oldsmobile, 307-455, Kit. Nov 21, 2018 · Oldspower is the Original Oldsmobile Performance Site. ∙ 7y ago. Add your answer: Nov 24, 2012 · Hi, im in the progress of buying a 1979 Trans AM and have researched a lot on how to improve performance from the measly 185hp it put out. 921" variety. 447" that is a 1/2" bolt . 5a heads are rumored to flow slightly better. Dec 9, 2003 · The 86 307 will not have the 7A heads, it will most likely have the 6A heads. and 1980-1/2 to 1985 307 c. The 7A 350 heads are totally different. The previous owner of my cutlass spent a sh*t load of money on that little 307. You have 7A heads. 78 Cutlass Calais; 260 with factory 5 speed manual. Does anyone know of any options for the camshaft? Not wanting anything huge just an upgrade from the vin Y tiny camshaft. Dec 19, 2024 · 1500-6500 RPM Power! The Edelbrock Performer RPM intake manifolds for 330-350-403 c. I have a vin 9 307 in my 85 442, and I have found this site to be pretty useful. My guess is that you have a massive mismatch of parts. Part Find OLDSMOBILE 5. 08 Type O, 88 CSC RIP, 94 Z71 Olds 350 TBI, burned to the ground, 2000 Dodge This MABBCO cylinder head is for a GM Oldsmobile 5. 5As would allow you to use aftermarket intakes and they flow a little better. Jan 3, 2010 · couldn't find specs on port sizes, but I will say I have seen 7A heads and it's pathetic. 3 x 1. Apr 27, 2014 · With the exception of the 7A heads on the 1985-90 307 motors, all Olds motors use the same exhaust flange gasket, so all headers will physically bolt to any Olds heads, but the different deck height means that the big block motors need headers with different primary pipe routing from the small block to clear the frame and bottom of the firewall. 7A-A5 intake 5A heads A4 Intake. That's 1. 875" intake/1. Other big differences between 350 7a heads and the 7A 307 heads, the 307 heads have no center divider in the middle exhaust ports and they have smaller valves. The headers off a chevy Dec 1, 2008 · They are a tiny bore motor, much like the 305 chevy. They also have the same 1/2" head bolt holes as the 403, whereas early 350 heads only have 7/16" bolt holes that must be drilled out for this swap. Up through Mid-85, 307's had normal 5A cylinder heads and normal hydraulic flat-tappet lifters. 500 is 1/2" 7/16" bolts would Oct 14, 2011 · the vin 9 307 was available from 1986 to 1990 in cadillacs a vin 9 307 was essentially the same motor used in the 442s. 542/. oldsmobile fabricated sheet metal valve covers 307,330,350,403,400,425,455 (black) $ 259. #7a (it's actually a capital A, but small subscript compared to the later model big script 7A 307 heads) heads from 1972 were the same with the exception of the exhaust seats being induction hardened, once again, no big valve variation. The head's labels are 5A and 7A, while the engines are Type Y and Type A. The last year for Vin "Y" code 307s with the conventional valvetrain was '84. The last thing you want to do is lower compression with larger chambers. 563 lift cam, 1 3/4" American Racing headers, 2 1/2" Pypes X-pipe exhaust, Qjet. 6 sq inches. “ This is a used bare small block Oldsmobile head, ready for machining. With the right seat cutters, the bowl is larger and the bowl shape allo Find many great new & used options and get the best deals for 1972 Oldsmobile 350 Engine 7a Heads at the best online prices at eBay! Free shipping for many products! In fact, the 7A 307 engines are rated at 10 more lb*ft than the 5A engines are. The A in 5A and 7A for the 307 heads is the same size as the number it's next to. 58 cc. Post subject: Re: 1987 307 7A Heads. 060") with the old-school gasket. ” BARE Oldsmobile used core cylinder heads, each. Get some 5A heads (literally almost double the port size) and shave them down a bit to get closer to 9:1. 08 posi 8. CFD stands for central foundry. Jan 9, 2013 · That's What She Said! 71 Monte Carlo, 468 BBO, 400 turbo with B&M shift kit, 4. In reading articles on this Engine it sas 7A Heads From the 87 307 Flow very poorly which basicually you can't build, add headers or any of that jazz. 750" diameter. . 060" gap. Shop Cylinder Heads & Parts for Oldsmobile Cutlass with eBay Guaranteed Fit. With 67cc of combustion chamber volume and an intake port height of 2. You will have to ream out the bolt holes for the 403's 1/2" bolts and add the steam holes. Dec 19, 2008 · From what I've heard over the years, your best bang for the buck is the '71 "7" or '72 "7A" heads from a 350. The Performer RPM is the best performance intake for a street Olds V8. The 5a ports are larger than the 7A's, so this makes sense. The intake valves in the 307 heads are 1. An easy ID is the heads. com May 8, 2007 · It is likely also an 8. Check out realoldspower. In stock form with the 7A heads, they are about as wheezy as you can get. 1980 - 1984: "Y" motors, 5A heads, flat lifters, mild cam Nov 4, 2004 · Unless you plan to shave the heads to re-gain compression, it wont help. 92 no slip, project nightmare, 2017 Dodge Challenger GT AWD Go Green Towing Machine Mar 20, 2007 · In other words, the 5A headed 307 was technically rated at about 5 more hp, but with less torque, compared with a 6A or 7A headed 307. Apr 24, 2013 · If you went with an aftermarket ( aka 'normal' sized runners/ports ) intake, it wouldn't match up to the tiny intake ports on those 307 heads. The ports are exactly half the size of 5As. I recently blew a head gasket on my 87 Regal w/307 v8. I am an LS guy. 5" Type "O". 7A heads, aluminum intake, ect. I don't know what you have for pistons in that. sorry as far as 307 heads i do not know what size headbolt they use as none of my books can tell me since 307 are never built up and have very few preformance parts if your head bolts measure . Feb 7, 2004 · The reason for the poor figures in the 1986-90 307 9s is because oldsmobile went to heads that had the same intake and exhaust runner size that chevy uses(6A, 7A, small tubular instead of large square bore). the 307 is a reliable work horse, great for daily drivers, not much of a performance engine. That wouldn't be good for anything. They're about as big as your thumb. 3". Lets wait for Joe P to comment he up on olds stuff more then me. Could you find some 6, 7, or 7A heads? They have the same ports as #8 heads, but a 66ish cc chamber and would give you better compression, torque, and fuel efficiency. Get no. Apr 2, 2008 · yes,1970 block is the way to go,reason behind this is simple-more power,stock compression is bigger than the 72's (unless it has heads shaved and moded)and has if any little to no smog equipment on it like egr. I believe that the Hurst olds from 83 are larger valved heads, so this represents an option. Also, the 307 heads used a bigger head bolt. JMO. The good news is that the 307 heads have smaller combustion chambers than the 403 heads and will raise compression. Because you have a late model 307 (aka the roller cam version with the 7a heads), there is not much you can do without swapping the 7a heads for 5a heads. 0 307, model years 1985-1990. The 6A and 7A heads fit the later ('85-'90) roller lifter 307s. i. In fact, the 7A 307 engines are rated at 10 more lb*ft than the 5A engines are. gasket part #9422 and they fit but on the corners there is a whole that looks like a bolt goes in but on my 307 there is know bolt for the whole on the vavle cover. 3" by 1. (!?) You'll need to mill the heads to get there, but that's the The heads are much lighter than the Olds-cast units, I believe they started showing up about the same time the blocks got the windowed main webs -- I don't know 100%, but I'd bet most of the 307's and some of the last 350's might have these heads on them. There are not many 6A heads going around so that gives me the idea that GM must have not liked the design or they would'nt of started using the 7A heads. d. The 307 was also the last carbureted V8 that General Motors manufactured. please help!!!!! The 5A heads were used on the '80-'84 "conventional" (non roller) 307. In 89, those would be 7A heads. The 80s head has a large capital "A" that's the same size as the 7 and in line with it. I got everything together and I am having problems getting it to run. 00 Dec 26, 2009 · i wanted to switch my 307 w/ 7a heads to a SBC either 305 or 350 because of the large amounts of cheap speed parts i drive a 1986 cutlass supreme w/ a 307 7a heads open air cleaner hallow cat with flow master dual out rear muffler and B&M z gate shifter on my Th350 trans. It has a mean misfire when I give it gas. motor has just over 40K original miles when pulled. If you have later heads with the 80cc chambers, you can swap the early heads and raise compression without changing the pistons. But if it's still a 307 Y roller pig, there's really no need for a performance intake. Jan 25, 2007 · Finally, as an interesting data point, the NHRA lists factory blueprint specs on line. Oct 23, 2012 · 1970 Olds Cutlass S, Forced Air Olds 358 SEFI Cutlassefi tune Terminator X Max, 2. 3" by 2. I pulled the carb. Budget Engine Rebuilders (484) Headlight Assemblies for Peugeot 307, Cylinder Heads & Parts for Oldsmobile Cutlass, Jun 12, 2011 · If it has 5a heads, its a 1980-84 non roller engine or 1983-1985 vin "9" Aka high ouput 307. We have a great online selection at the lowest prices with Fast & Free shipping on many items! Can olds 307 7A heads fit on a 403? Updated: 9/26/2023. 99 add to cart; oldsmobile bare set aluminum heads 330,350,403 and 400. Add your answer: Roller lifters and cams were in all 1986 and up 307's, and most 1985 307's. 000-inch-diameter intake and 1. Late style crankshaft bolt pattern. Don't get them confused with 85-90. Nov 17, 2020 · I believe there is about 10 to 15cc difference between the early Olds 350 heads and the 5A 307 port size. Feb 5, 2009 · hopefully this helps cause it helped me "The 5A heads were used on the '80-'84 "conventional" (non roller) 307s. Jostain luin että laahurinokkaisen alle '85 Vin-9:n tunnistaisi kumivaimennetusta ja ulkosivultaan leveämmästä dampperista. Oct 21, 2020 · I know nothing about olds motors, and very little about classic carb'd motors to begin with. 625-inch- exhaust valves from the big-block. customer: how can i find out if my 1984 olds 307 with 7a heads is a rollerlifter roller cam engine? can i replace with 5a heads, intake, and exhaust and still use roller cam/lifters or should i replace with flat tappet cam to save time and money are lifter bores the same size? Jun 11, 2008 · The 7A heads with the large A on the 307 (not to be confused with the 7A heads with the small A used on the 71 350s) have horrible ports that can barely support that motor, let alone a 350. Now, to thoroughly confuse you, Olds made two different version of each of these engines. Cylinder Head Bolts, High Performance, Hex Head, 1/2 in. But at around 8 to 1 with poor flowing heads and your 84 has the better heads, only minor improvements can be done. Just ensure you know what you're buying. 99 add to cart; oldsmobile 307, 330, 350, 403 polished dual plane high rise intake manifold (will fit 80 cc aluminum heads ) $ 549. Oct 11, 2006 · The 7 A heads used rotators on both intake and exhaust, so the all the spring pockets are cut deep. The ports are 1. Getting stressed out with this car, could use some input. Oct 30, 2003 · olds heads your 5A and 7A castings are 307 olds heads the 4A castings are the only 403 heads. Jul 25, 2022 · Now I believe 7A heads were 307 heads from the 80's and were even worse then 4A heads. off and took it to get rebuilt. In 1986 and 1987 Oldsmobile perfected the design of the 307 with a roller cam and lifters and incorporating a swirl port design 7A head with smaller ports. Apr 23, 2022 · 5A heads are from a 307 Olds. The short blocks are all the same, and a "newer" 307 doesn't exist. 92 no slip, project nightmare, 2017 Dodge Challenger GT AWD Go Green Towing Machine Can olds 307 7A heads fit on a 403? Updated: 9/26/2023. 99 add to cart; oldsmobile 400,425,455 alum intake manifold 4150 open plenum (satin) $ 389. Sep 18, 2007 · The 6A heads are kinda a mystery, they are found mostly on early 85 GM cars with 307s, the 7A and 6A share the same (A5) intake and the 6A heads also has the smaller swirl ports as the 7A heads. ) 85-up "y's" had smaller ports & its own unique A5 intake. Personally, I'd get a 5A head 307 flat tappet for an 83 if you get a choice. 7L/350 Cylinder Heads and get Free Shipping on Orders Nov 10, 2009 · I removed almost all emissions components and my olds 307 ran fine. The 5A heads were used on the '80-'84 "conventional" (non roller) 307. They can be made to perform fairly well. Be careful on the 7A heads, since the late 1980s 307 used a different 7A casting. I'd recommend the #8 heads used on 73-76 Olds 350s. 69 sq inches of flow area. We are not sure what year the engine is exactly. com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon. Sep 5, 2005 · 7A '85 - '90 307 67 0142 This 'A', and the others from 2A to 6A, is a large capital letter equal in size to, and immediately adjacent to the 7, like | 7A. It is my contention that the 7A is the single worst head GM ever created as far as flow, followed closely by the chevy TBI swirl port heads. 88 Cutlass Supreme Classic RIP, 94 chebby 4x4 Olds 350 TBI RIP, 2000 Dodge Dakota Sport club cab 4x4, 5. I would ask the guy if the 72 and 70 are stock,like for example,if the 72 is cranking out 100 hp more than the 70,than get that. I assume the numbers you gave me were for 6a or 7a heads. Apr 23, 2013 · The 1972 350 had 7A heads, but while it was a capital A next to the 7, it's smaller than the 7 and written almost like a subscript. 080" (and later R46SZ with the smaller gap preset at 0. The 5A heads are still horrifically pathetic, but they are easily twice the head of the 7A. the port size is smaller on 7a heads. Dec 29, 2008 · If you have the 64 cc heads (casting numbers 1 through 7 and including 7a - though not the 7A heads used on the 307 motors) then you need new pistons with the correct dish volume. 3, 1. (D heads run 72 CCs). Jun 23, 2004 · If your 307 has the 6A or 7A heads, the gap is a more conventional . Roller cammed 307s used 7A head. You could probably use a stock 307 cam. Here's my problem. 541 112 LSA, 2350 stall 2004R, 3. I've been reading up on the olds 307's Currently purchasing a 1987 442, and also a 1987 Cutlass Salon. Shop Oldsmobile Car & Truck Cylinder Heads & Parts with eBay Guaranteed Fit. All the late 70's heads with the big "A" after number have awful, restrictive exhaust ports. This head is preferred for 307 performance use because there are port matching problems between aftermarket intakes and exhaust headers with the 7A heads. If you compare the port size (CSA --- cross section area) of the 307 7A heads (1. Casting # available 2a, 3a, #5a, #7a, #7A, #10, #8 each. The most common modification done to these small-block Olds castings is to install the 2. Toggle signature 70 Cutlass S, Forced Air 9. Those have much smaller ports to match the 7A heads. Apr 2, 2008 · 1970 Olds Cutlass S, Forced Air Olds 358 SEFI Cutlassefi tune Terminator X Max, 2. Vin-Y:ssä dampperin ulkopinnan leveys on jotain sentin luokkaa ja se on yhtärautaa. There should not have been any factory installed 5A heads on '85 Toros. I also removed the charcoal canister and all the hoses from it. tom Get the best deals for Olds 307 Head at eBay. com for some pretty good info on the subject. it appears that in '71 (when they needed to drop all of the compressions in GM cars - 10. That's when I found out that I have a 1985 Oldsmobile 307 in the car. All a roller 307 vin 9 motor needs is a set of 5A heads off of an 85 and below 307 and the A4 intake to make some real power. Wiki User. 0", or 2. 350 olds heads on a 307 would cut the compression even lower than it already is and would kill the torque output. The gas 350 with number 8 heads were dished, and compression was low. 8 buick (355 in the making) T350C(thanks to a couple guys on here for Cylinder Head Bolts, High Performance, Hex Head, 1/2 in. Stock intake, carb, and i left the EGR still functioning. The 330 heads do have larger ports than the peanut-port 7A heads used on the 1985-1990 307s, but you'd need to change intake and exhaust manifolds to make this work. Why would you want to use them. no other valve sizes were offered. Drive ability is markedly better with 7A heads than 5A heads -- it almost feels as smooth as fuel-injection! Engines: Oldsmobile V8s: Differences between the Y and 9 engines. 67 out of 5 stars The heads are much lighter than the Olds-cast units, I believe they started showing up about the same time the blocks got the windowed main webs -- I don't know 100%, but I'd bet most of the 307's and some of the last 350's might have these heads on them. 5 to 1, Gen 3 Edelbrock heads, Olds 358 Mahle 1mm forged pistons, Molnar rods, 330 internally balanced crank, roller cam 218/218 . Note that you should not confuse the 1972 7A heads (where the upper case A is about half the size of the 7) with the 1985-1990 7A heads, where the A is the same size as the 7. Scrape the grease off and it will tell you what heads you have. Amazon, the Amazon logo, AmazonSupply, and the oldsmobile 307, 330, 350, 403 dual plane high rise polished intake manifold for 69 cc aluminum heads only $ 749. [ Thanks to Chris Witt, Greg Beaulieu, Tom Lentz for this information ] Feb 29, 2024 · In this episode i give you a quick look at some 350 Olds heads I picked up for a really good deal and a Holley intake!Follow along on Instagram @mod__everything The 6A heads are kinda a mistery, they are found mostly on early 85 GM cars with 307s, the 7A and 6A share the same (A5) intake and the 6A heads also has the smaller swirl ports as the 7A heads. Bare means there are no parts in them, and you cannot install them on a car. 0 to 1 compression. With the money you throw into making a Oldsmobile small-block cylinder heads have a number, like this popular number-7 casting cylinder head. 5) that their first method of doing it was to dish the pistons more. Jan 28, 2009 · From 1983 through 1985 the VIN 9 engine was a hydraulic flat tappet cam engine with larger port 5A heads use on both '83 and '84 Hurst Olds and '85 442. 99 add to cart Aug 20, 2009 · I picked up what should be a roller cam 307 a couple of weeks ago. About half-way through the '85 model year, they switched from the 5A to the 7A, and the change was responsible for a 10 hp loss. 8:1 compression. I wouldn't bother putting the 307 heads on a 350 Olds. Stamp number of a 5a should be 3317 as long as the car is an 84 or older 307, you should be good. All should have been roller lifter engines with the 7A heads. 541/. 99/1. Oct 29, 2008 · #7 heads from 1971 had 1. 44 CR, Edelbrock RPM intake, Crane roller 222/230 dur . 035" or . 0" by 1. Yep, Olds made a 307 from 1980 to 1990. 8:1 with a stock HP rating of 140. There are not many 6A heads going around so that gives me the idea that GM must have not liked the design or they wouldn't of started using the 7A heads. Mar 11, 2012 · Muistankohan nyt oikein, että kaikki Olds 307 rullanokkakoneet (kansikoodi 7A) on samoja nokka-arvoiltaan. It'll physically bolt up, but the peanut port 7A heads won't match up port-wise. That's why your '86 has 7A's, and my early '85 442 had 5A's. The other small Olds heads frequently have 2. You must specify which casting number Jan 7, 2010 · Good news/bad news. The heads are much lighter than the Olds-cast units, I believe they started showing up about the same time the blocks got the windowed main webs -- I don't know 100%, but I'd bet most of the 307's and some of the last 350's might have these heads on them. Just get a normal aluminum factory A4 intake if you go with the 5A heads. If its Oldsmobile powered, we want to know about it, and make it go faster! OldsPower. 307 67 5844 7A '85 - '90 307 64 0142 This 'A', and the others from 2A to 6A, is a large capital letter equal in size to, and immediately adjacent to the 7, like | 7A. The 72 350's came with 7A heads,were as 70's had #6 cast Dec 2, 2008 · does anybody know where they sell chrome valve covers for a oldsmobile 307 with 7a heads, i bought some from summit racing mr. Take the intake off and look at the ports. These are still readily available and relatively cheap. Step one: find yourself a pair of "5A" heads/A4 intake and get yourself the rollar camshaft (which summit does not sell), you can find this camshaft through advance-auto or the like for $250. I removed the air pump and all the lines, plugged up the holes in the heads with 1/4" pipe plugs. com and pull down the tab that says "RULES". This cylinder head is identifiable by its #142 or #7A casting number. The Salon i wanna get better performance wise. Here a good link for engine part numbers: Olds FAQ -- Heads Apr 19, 2011 · Up through Mid-85, 307's had normal 5A cylinder heads and normal hydraulic flat-tappet lifters. Aug 5, 2019 · The only heads worse than them are the other #A heads. The 5A headed VIN 9 307 was rated at 180 hp, and the 7A headed VIN 9 307 was rated at 170 hp. 3" x 1. To put big block (400, 425, 455) heads on a small block (260, 307, 330, 350, 403, 350 diesel) you'll first have to drill out the dowel holes in the heads. Your best option for a 307 is a Cam, a good exhaust, and a set of 442 307 heads. That makes one sweet roller 307, and since your digging that far into the motor, REPLACE THE CAM! That is worth 40 HP right there but will cost you a good $200. 7A '85 - '90 307 67 0142 This 'A', and the others from 2A to 6A, is a large capital letter equal in size to, and Feb 24, 2003 · Changing out the 7A heads (note large ?A? for late 80s 307 and little ?a? for early 70s 350) for 5A (307 heads before 1985) can improve the flow above 4200 rpm, but these are not high reving engines to begin with. At the head opening is similar, the inner port is smaller on the 5A heads. 5 posi, Black and Yellow 81 Cutlass Supreme, 231 NA 3. 69 sq in) to the Jul 30, 2006 · I bought a set of 350 #5 Olds heads 7A. Your intake manifold should have "A4" stamped on the front left side (drivers side. ∙ 8y ago. 85-up "y" engines had 7a heads & were a roller engine. May 8, 2009 · You'll be shocked that it makes the 140 advertised HP it does. Jul 15, 2012 · 85 Olds 442; 440 Olds ( bored/stroked Olds diesel 350 block ). For the Oldsmobile 307, are the cam and roller lifters from the 7A head motor compatible with the 5A heads? This thread is archived The heads are much lighter than the Olds-cast units, I believe they started showing up about the same time the blocks got the windowed main webs -- I don't know 100%, but I'd bet most of the 307's and some of the last 350's might have these heads on them. 7L/350 Cylinder Heads and get Free Shipping on Orders Jun 8, 2020 · Assuming it's the Olds 307, 5A heads used R46SX with preset gap of 0. Part Number Find OLDSMOBILE Cylinder Heads and get Free Shipping on Orders Feb 2, 2024 · Edelbrock made 2 intakes that will fit the 307 ignore the that the box say chevy, it will take you to the Olds manifolds The 6A heads are kinda a mistery, they are found mostly on early 85 GM cars with 307s, the 7A and 6A share the same (A5) intake and the 6A heads also has the smaller swirl ports as the 7A heads. Jul 24, 2009 · CUTLASS Olds 7A heads. The 307 has swirl port heads with tiny ports, nearly everyone complains they are under powered. Jul 24, 2004 · Anyone know if you can swap a Olds 4bbl 307 intake on to a Olds 260 V8? I have 76' 260 with #10 heads and #1 iron dualjet (2bbl) intake. Driveability is markedly better with 7A heads than 5A heads -- it almost feels as smooth as fuel-injection! Below is a table with pictures that shows the differences between the 5A and 7A heads. a 403 Olds with #5 or #6 or #7a Olds 350 Heads will roar. Feb 21, 2006 · Intake manifold -to- head ports too small = fiction. D3A 350 3948 Diesel. 4, 5, 6, 7, or 7A heads from the late 60s-early 70s. The easy way to tell is to look at the letter code on the cylinder heads. Cant even seem to find a replacement cam for the vin 9 engine which would be pretty decent. 6 sq in), but those ports were oversized to begin with on a 307 (making them lazy from a port velocity viewpoint). 3", or 1. Apr 9, 2014 · You will have port mismatch with the 7A heads and have horrible performance if the engine will even run right given the fact that the intake heads on those roller engines are much smaller due to the need to increase the intake velocity with the swirl port design of the 7A heads. The Buick is a whole different critter. 40 over,ported the heads,installed new internals and added a DUI distributor. The only issue on the 72 350 is huge dish pistons, so stay very conservative on the cam, unless you swap the pistons. You'll find engine blueprinting specs. it came with the single snorkel intake as opposed to the dual snorkel one since there would be nowhere to route the second hose to. 📣 Request Answer. He had the engine rebuilt,bored . The smallest 350 intake valve is 1. Olds 307 5A/7A heads question . Apr 23, 2013 · DON'T put on 307 7A heads on your 350. Part Number: EDL-3711 4. 5A heads have no roller lifter, 7A heads have the roller lifters. Where Olds heads vary a lot is exhaust ports. Jul 22, 2007 · The best bet for small block heads are #5 (68-69), #6 (70), #7 (71) or #7A (72). Oct 28, 2010 · From the factory, the 81 Olds 307 came with 7A heads and 7. 350 intakes can fit on a 307 5A head car. it did For sale. 625 valves used on the 1987 307 7A Heads Page 1 of 2 [ 22 posts ] Go to page 1, 2 Next: Previous topic | Next topic: Author Message; 442WMachines: Post subject: 1987 307 7A Heads. Part Number: FEL-CS8171-2 4. Jan 10, 2005 · I think he is talking about putting OLDS 307 heads on an OLDS 350. Just do not get the tubular welded manifolds used on the 1985-90 307s. cfzfpkqx mimfhk eucs nkhv ttrkl dayy zxlb dzookov upymph bhib