I just purchased a 351C CJ, 4V 4 Bolt Main P/N: D2AE CA. Crank P/N: D1ZE-6318-AE, Intake Manifolds P/N: DOAE-9425-L w/ Exhaust Manifolds D1ZE-9431-BA & DOAE-9430-G. Is that all correct?


Asked by Nov 18, 2011 at 09:16 PM about the 1970 Mercury Cougar

Question type: Car Customization

Would this combination of parts go together and what type of compression would be right for the set-up? There are no connecting rods or pistons although the cam and rockers are in place. Im thinking .030 over is all I need w/ a upgraded distributer system and maybe later on an EFI. Nothing radical, just good looking and dependable will surfice.  Thank you

2 Answers


Jet124, I'm a big fan of the 351C, maybe I can offer some usefull info for you?? The combo of parts you have WILL go togeather just fine, Seeing how you have to buy pistons you can decide what compression ratio you want for the engine (I'd suggest a 9:1 considering the available octane levels of pump gas). The overbore of the block isn't for me or you to guess on. That depends on what your machinist determine it needs to true up the Cylinder walls, although I'd recommend staying with a MINIMAL overbore. (Who knows, you might not need a .030 or greater overbore). As for ignition, a pertronix igniter is all you need to upgrade over the stock points...You can spend as much as you like on an aftermarket Dist, coil, box...etc, but all you need for good street performance is a rebuilt stock Dist and a pertronix unit.....just food for thought. Radical? That is going to depend entirely on the heads you use on the engine. You gave part #'s for all the items you have, but made no mention of the heads. I assume you have heads on the engine just because you said "Rockers are in place" Block: (You know what you have). There is ALOT of myth involved with 4 bolt main Cleveland blocks. Although I only have about 25 years experiance with them, There are people in the world that have alot more experiance than I do, and have put Cleveland blocks under alot more stress than I have. I have to totally agree with the words of this man..."I've Pounded the crap out of 2 bolt main cleveland blocks just as much as the 4 bolt blocks, I've never seen an ounce of differance in the strength between them".... Jack Roush. With that said, you probabally paid a little more than was realistic for the block, but it's all good. Alot of the 4 bolt blocks were used in Montego police cars with 4 Bbl heads, maybe that's where yours came from. (I have a couple of them from that original application) Your intake manifold: Probabally not original to the engine (provided the rest of the components are original to each other). The intake is a 1970 piece with the Holley flange. This was always a popular swap for the later spread bore intakes that limited carb selection. The intake you have is a good one to have (my personal favorite for a street engine) Crank....????: The crank P/N you gave isn't for a crank. It "Looks" like you took it from the balancer and possible got a couple of the #'s/letters wrong. The #6318 isn't valid for anything.....A balancer # would be 6316, and the suffex "AE" isn't known (at least to me). The "Correct" balancer P/N for a 4 barrell Cleveland would be D1ZE-6316-AB. Maybe that's what you have and just read it wrong??...easy to do, no sweat. The CRANK would be marked "4M" I'll attach a pic for you to see where it's at. You'll have to pull the oil pan to see it. Exhaust manifolds: Like the intake manifold you have they are correct for a 4 BBL application...71-73. To get (buy) an "H" pipe to work with them, you'll just have to get the 71 and up H pipe.....the 70 H pipe won't work with the pair of 71-73 manifolds you have...but, they will work just fine in a 70 Cougar. I don't know what engine you currently have in your cougar, if I did I could offer some better advice on what you'll need to do to make this swap possible. No matter what, it's not goung to be difficult. If you've never had a car with a 4 BBL 351C, you'll be in for a big supprise. Might be one you like, might be one you don't like. The engine is an "ALL or NOTHING" engine....meaning it runs HARD and STRONG at high RPM's....and it stumbles and chokes when it's not revving high. A great engine to build if you want to do nothing but run it hard, but for use in a stop & go daily driver it's gonna do nothing but hog gas and drive you insane....lol (not very suitable for a non-race prepped automatic trans either) It's something you just have to experiance for yourself...Most people use thier cars the same, they drive them normally 98% of the time but like LOTS of power available for the 2% of the time that they want to beat on thier car. The 4 BBL 351C makes most people very miserable for 98% of the time, and very happy 2% of the time. Gotta love it. Riff.

2 of 2 people found this helpful.

Riff, Thank you for the detailed and informative reply. I did mistake a few items so let me list them again. Block: D2AE CA - 2C25 & Crank: 4MA - N/A & Balancer: D1ZE-6316-AE - N/A & Oil Pan total = ($550.00), Heads: D1ZE DA - 2C25 & 2D6 ($200.00), Intake: DOAE-9425 DA - OE5 ($120.00), Exhaust: D1ZE-9431-BA - 2D17 & DOAE-9430-G - 2E11 ($249.00). I had always thought .030 over was a minimal bore but if I can get away with less then thats the way I would like to go. If 9:1 is a good compression ratio that works for today fuels, again that would be the path to follow. Would a triple angle valve seat and valve lip be adviseable? I like the quote by Jack Rouche. I was working in the engine shop for America West Airline with a guy who was building an early ninety's mustang 5.0 and he sent an idea to Jack who inturn had one of his guys build him an "exeprimental" manifold on the house. He's agreat guy but him and Hendrick should stop flying. Riff with the new info in hand would this parts combo work? Would you recommend changing out the Intake manifold if it even works with this setup? As for the Distributor, Coil and Ignition System I will look into your suggestion as this is not something I readily know about. I am also looking into the installation of a T6 Transmision.

1 of 1 people found this helpful.

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