SlowGT:
The math goes something like this for your stock 5.0 engine:
4.00 bore x 3.00 stroke x 3.141592654 (Pi) x 8 = 301.59 or
302
My 331 goes like this:
4.06 (which is a .030" overbore) x 3.25 x 3.1415 x 8 = 331.62 or
331
And the 347 kit:
4.06 x 3.40 x 3.1415 x 8 = 346.93 or
347
I personnally like the 331 kit for my application - which includes a ProCharger in the near future. Makes for a well mannered street car that can open up a can of whooop-arse by just taking the rpms up a little.
E