Quote: jim, can you explain how the 4.25 crank fit better than the 4.15? oil pickup boss and cylinder notching? so, what kind of power do's your 440-1 13:1 motor make? whats the car weight and whats it run?
As John pointed out, the BB Chevy rod is smaller on the big end which clears the cylinders and oil pickup better, even with the slightly long stroke of the 4.250" vs 4.150".
My engine has not been on the dyno, but at 3250 pounds in a 1969 Dart it runs 9.15-9.30 depending on weather. And that is with a flat tappet, solid lifter cam (Comp MM305S-10, 279/287 at .050", .650"/.630" lift). And my heads are nothing special, just decent hand porting (355cfm).
