I learned cast crank is lighter than forged, cast aluminum pistons are heavier than forged, mopars 318/340 3.58" throw cast crank "might"require balanceing. And Scats cast 318/340 3.58" is already internally balanced as is. Therefore an economical desicion would be to - go with the Scat cast crank and forged pistons keeping the assemble lite as possible. And H beam rods are roughly 700 grams bushed and Scats are 643 grams. I know you don't believe it, but I would put this lite rotating assemble in my engine and use the neutral balancer on front and not pay for t machine shop...figuring a bob weight ect. Figiting over the last fews grams of unbalanced weight somewhere. Sincerly Jesse