All B motor forged crank engines are internal balance. All B motor cast crank engines are external balance and use the same imbalance. The 440 cast crank engine also uses the same imbalance.

With its 2.625 mains and 2.375 rod journals, and the 3.375 stroke, the B motor crank should be nearly indestructible. It has a lot of overlap and the short stroke puts much less stress on the crank.

Looking at it in that light it's hard to say a forged crank has any benefit until you hit 6500rpm. As a matter of fact as the cast crank is lighter it may actually be quicker to accelerate.

So IMHO save your money on crankshafts and put it into pistons and if you have any left over, rods. A lightweight forging with the proper compression height is the key to a higher performance engine. I think you can take 150 grams off each piston/pin and then that 383 will really like to rev.

On the other hand if you want a torque monster there's no substitute for cubic inches and the best way to go that route is increasing the stroke.

R.