Which way to go - 390 406 428 stroker

[PaulProe]

I am in the process of building a motor and looking for help in determining where I end up.

1) To be period correct, it needs to be an FE. But my budget can't afford a side oiler.

2) I have a 68 360 truck motor, that appears to be bore-able a slight more, maybe to 4.13. I have a good 390 crank for that block. I need to buy rods and pistons.

My options are to build it as a 390, bore it (assuming it will pass sonic) to get to 406. If it will go to 406, I could add a 428 crank to be a 428. Or I could stroke the 390 to come in around 430.

My hang up is the badge on the side of the car says "427" 390 or 406 won't pass this test - it becomes a pride thing. 428 or 430 would at least satisfy that test.

I don't see a lot of guys running 390 strokers so there isn't a lot of "this is how I did it" out there.

Can anyone throw out ideas to help me with the decision? I have a friend who has a Superformance with a 347. His regret is he didn't go to 427. Don't want to finish the car and end up with "builders remorse"

The car will strictly be a cruiser. Only looking for moderate street performance. The 390 would be more than enough power, if that is the wisest move. But I am trying to build it as period accurate as possible.

Dollar wise, each cubic inch = $$. 390 obviously would be the cheapiest. But since I already have to buy rods and pistons and probably grind the crank, the difference to the 428 or the stroker kit isn't that far off.

Comments or suggestions

Thanks

Paul

[jimmymac]

What do you want? Iv'e seen two 360 blocks bored .080 4.13 with a 428 crank you get a 428 add some quench pistons youve got a strong engine. Dont need power? really! Add a 390 crank w/pistons slight bore to clean up the cyls. Or build a 360 with aluminum heads you could build 350HP. just use that quench as in a flat top piston. Its just free power. One Hp per ci is not to hard to get. There's the 406 option 390crank 4.13 bore very good,For higher rpm or lower. Do you have acess to any crankshafts,could be the deciding factor. remember 428 are ext. balance requires different flywheel and front balance dampener others do not.
Good luck Jimmymac

[blykins]

FE stroker kits are very common. You might wanna give Keith Craft a call. He builds 550hp stroked 390's all the time.

You could take that block, clean it up with a .030" bore...and use a 4.125" or a 4.25" stroke crank. That would be 431 or 444ci.

Add some Stage 2 Edelbrock heads, a hydraulic roller cam, and you'd have some good streetable, reliable, horsepower. And you'd still be period correct.

[wtenukl]

I bored my 390 .030 and bought the stroker kit from Scat. The crank is a 4.125" and I put in Ross pistons etc... I have dual quad Holley 600's and a pretty mean Comp Cam. The only difference I noticed, besides the tremendous increase in torque and horsepower, is that the engine doesn't care for low rpms very much. But when you get on it.......look out. My total cubic inch is 431.

This build wasn't the cheapest way to go, but I firmly believe it will give you the power and look you are looking for in a period correct engine without having to "break the bank."

Good luck,

Todd

[farmallmta]

First, congratulations on your choice of FE for the Cobra. It's the natural way to go, with possibly the most beautiful engine ever out of Dearborn under the hood as a result.

If budget and streetability is your consideration, the 360/390 block with 0.040 overbore and oil mods, Edelbrock, 427, or CJ-valved 406 heads, hyperuetectic or forged pistons with compression ratio between 10.5-10.95:1, a mid-performance cam with SOLID lifters (flat or roller) with adjustable rockers (check out CamResearch cams... they can pre-run-in the cam for you as well as custom grind for your specific needs!), a 390 crankshaft and stock rods, Edelbrock Performer 390 intake and Holley 600 carb, stock distributor with Pertronix module... it is just a great performer, totally kicks Corvette A*s, and is reasonable to build. AND SOUNDS AWESOME with Spintech mufflers... as good sounding as a 427.

I fully understand the pride thing. If that is a close second to budget, then by all means install a stroker kit, additionally, to get you to 427ci. NOBODY among us FE buffs is going to give you any guff for stroking your way to 427ci rather than boring. It's ALL good. The engine will rev a bit slower than the 390/406/427 3.78 stroke, but give you great 428 torque as a tradeoff. But the rest of the build can be budget as outlined, as long as you blueprint and balance the engine carefully. Use an excellent machine shop, not a lowbuck Bowtie Bozo.

[Dwight]

I put "Powered By Ford" on my Cobra, but I do have a small block. I have a new set of .020" over 390 pistons for sale for $98 shipped. I also have 4 or 5 sets of used rods I would sell.



Dwight algunruner@aol.com

[Carnut427]

I strongly suggest you use new h-beam rods rather than old ones. Also, it cost me between $250 and $300 to have my 4.25-stroke rotating assembly internally balanced using heavy metal. Well worth the cost, but an extra expense you should be aware of.

Dan

[Naumoff]

PaulPro,
Go with the 431 stroker. Just rode in one. Very strong engine and keeping your bore size down it will make for a cooler running engine. I would also keep your compression ratio below 10:1 for pump gas use.
Cam choice will determine how pleasurable it is on the street at low RPM.

427 badges on the car. I thought that was the Model of the car not the engine size? Shelby put 428s in them and didn't change the badges. Just a thought.

[Barry_R]

Take your 360/390 and go 4.070 bore - - .020 over for the 390
Add the Scat 4.125 stroker crank, 6.700 H beams, and Diamond pistons.
We can get you a 9.8 to 1, 429 inch engine that way
It'll ship as a balanced assembly
Easy, reliable, fun
Call or e-mail for particulars

[Naumoff]

Originally Posted by Naumoff

427 badges on the car. I thought that was the Model of the car not the engine size? Shelby put 428s in them and didn't change the badges. Just a thought.

A 427 model is different than a 289 FIA model which is different than the Shelby Cobra. Right?

[KevinM]

Most 427 Cobras actually shipped with the 428 PI engine, so a 428 is a "Correct" engine for a Cobra. Many truck blocks will bore to 4.130". Have the bore sonic tested. If it will go 4.130" use a 3.980" 428 crank and make it a 428.

Kevin

[1985 CCX]

FE Confusion,

Kevin is right! The originals did not all have 427's. The first was a 390 and there was a handful (~40) with 427's. The rest had 428 installed, at least that is what I have read and have been told. The 427 badge is misleading to many as most do not realize that there are 2:1 small block cars over big blocks and out of the big blocks mostly 428's which I have found were not high hp scream machines. (somewhere in the high 300's) The big block cars were not the Cobra legends, that was the small block FIA's.

No matter what direction you choose remember that the car is light and 500hp is not necessary. An FE with modest hp will save you aggravation and money if you plan to drive the car at all. Moderation is key to reliability since it reduces heat build-up, wear, stress on entire drivetrain, and gas$$$$. Race cars are made to run a race then be rebuilt; street cars are made to drive. Any FE with ~400hp is more than enough.

[ZOERA-SC7XX]

For my ERA 427 I built a 390 with a 4.130 bore (it's okay) and a 428 1U crankshaft with std 428 KB pistons...and now I have a correct 428 w/ 68 cc heads for a 10:1 comp ratio. The cost was somewhere around $5000 without accessories...should make about 400 honest HP, which is fine for the street.

[ZOERA-SC7XX]

Yes and no