This might sound like a dumb question, but is there much of a difference between a supercharged 350 and a supercharged 383. The thing I am getting at here is if both are built strong, and feed 20 psi of boost is there gonna be a hugh power difference between the two. Here is what I am thinking about doing:

383, 6.0" rod, around 9.0:1, AFR 210cc Comp ported, Accel Pro-Ram intake with Accel 1000 cfm TB, Procharger F1 with 3 core sheet metal intercooler

or

355, around 9.0:1, AFR 210cc Comp ported, Accel Pro-ram intake, Accel 1000cfm TB, Procharger F1 with 3 core intercooler.

I am leaning toward the 355 because I already have a strong forged steel crank, and to build the 383 I would have to buy another crankshaft, which I will be willing to do if the horsepower out between the two is going to be extreme.

 

Well a 383 is 8% bigger than a 355, so theoretically it would make about 8% more power, but that's theoretically. You would probably notice more tq out of the 383, but that's due to the long stroke. Since you have the crank already, I'd build the 355. If you had to start from scratch I would go with the 383 since the longer stroke crank is just as much. FWIW, I'm building a roots blown 383, but only because I'm starting with just a block.

 

Theoretical power added by stroke increase: 3.8%
You'll never get a straight proportion with a displacement increase by either bore or stroke, only number of cylinders.
More info? Read my article:
http://victorylibrary.com/mopar/no-scale.htm

 

Intresting article, I didn't know it was that little of a difference...

 

yeah but you cant go completelly by that either.

figure it this way. if you had a N/A 355 making 420 horsepower (very very easy to do) and a N/A 383 making 440 horsepower (also very simple) then there is a 20 horsepower difference right?

So now you throw 15PSI of boost on each motor. the result? well technically if the MAT stayed the same you would see a 100% increase in power, so the 355 would be making 840 horsepower and the 383 would be making 880 horsepower...

so as you can see its NOT linear. the power increase does work on a %, but the bigger the motor, the more air it can move, and thats a fact. if you have a big motor moving a lot of air N/A, then stick forced induction on it, you will make more power than a small motor with the same PSI#. Volumetric efficiency will affect cylinder pressure which will affect torque which will effect horsepower at all rpms... so bigger is better, plain and simple.