318 build problems & new direction

The cast vs forged is seen in the casting line running down the 'spine' of the crank. That spine area will be all 'mooshed out' when forged; the cast spine will still be a sharp edge. Plenty of pix round showing the differences....

A '72 318 crank should be cast.

And I am repeating the advice from many on this point: With lighter rods and pistons, you ought to be fine at that HP level. (I have not done destructive failure analysis myself!) We have used a cast 273 in my son's 340 with SCAT I-beams and KB hyper pistons. The nice thing about those lighter parts is that it takes stress off of crank, AND, when you go to balance it, the shop will simply take off weight from the crank counterweights. And the 318 crank rotating mass is lighter too. Easy!

(And from what I have read the SCAT stuff seems to generally be better than Eagle.....)

BTW, is the block already over .020" or .030". IF the block is stock bore now, I'd just go over .020" to save some meat in the block for future rebuilds.