I've got a vehicle with a 400 engine, and a 3spd FMX transmission. I want overdrive, but they don't make a big-block compatable overdrive transmisssion small enough to fit in my car. So I'm wondering, since a 400 is essentially a 351M with a bigger stroke, any reason the 400 crankshaft won't bolt into the 351C and give me a 400 engine that will accept an AOD transmission?

 

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well the first problem with what you want to do is the 351c uses 2.5" mains, and the 400 uses a 3" main. Now they have been turned down to make that work, and I won't say it is a good idea or not, but by the time you pay for the machine work to turn the mains down, figure out the rods, and pistons for that combo etc, you might be better off buying a 393 stroker kit for the cleve if that is the way you want to go

 

I am not in any way putting down the Cleveland. As far as I'm concerned it was a masterpiece, but if you want more inches, you will be much better served by using a 400 block and building what you want. The Cleveland is worth much more as a 351 Cleveland.

My $0.02,
Doc

 

What kind of car? If it nothing rare cut the floor out and make a new tunall.

 

I think you can get/make an adapter to use an AOD.

 

302 2.5" mains
351C 2.75" mains
351M/400 and 351W 3" mains

 

thanks for correcting that, I made a mistake must have been half asleep when I posted

 

The counterweights are too big to fit inside the case.