331's and 390's

I am an active member of the HAMB and no one knows. I know the intakes are the same. The water pumps will interchange. I just was giving this board a try .
 
Dirty2 said:
I am an active member of the HAMB and no one knows. I know the intakes are the same. The water pumps will interchange. I just was giving this board a try .
Click to expand...

Hmm. I've plunked around over there, and iirc, some fellows claimed that the later heads flow better and fit the 331s. Iirc, the changes occurred in '56, but don't quote me on either case.

Dave
 
i have run the 390 heads on the 331 engine.
i used 390 pushrods, rockers, shafts, to make everything work. (and exhaust manifolds)
there was a very big difference in preformance.
 
They bolt right up and it works well. The chamber on the 390 heads is a little different, so we generally use an after market forged piston with the valve reliefs in the right place. It will work with stock pistons if you have a small cam, but if I remember right, the compression ratio drops a little (but still makes more power). The early engines had crappy compression ratios anyway, so if you really want to make some power, you will have to get after market pistons. It isn't too hard to make it a revver and get some really good HP if you are going racing (like over 500 HP).
 
Anyone have pics of the 390 head ports? I saw a stock '49 331" going together at a local shop. I can't see how they made the power that they did.

Dave
 
bill said:
i have run the 390 heads on the 331 engine.
i used 390 pushrods, rockers, shafts, to make everything work. (and exhaust manifolds)
there was a very big difference in preformance.
Click to expand...
You didn't have to use 390 cam shafts?
 
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