need input on 318 build

It should balance just fine, but it will need weight removed off the crank. No biggie.

I had my 318 balanced, it has a cast crank, Eagle SIR I beams and JE forged pistons. Mine is at-

Piston and pin = 593 g (the forged JE's are light!)
Total rod weight = 604 g (rotating + reciprocating)

Balanced just fine, way lighter than stock though so some weight had to be removed from the crank.

The only thing I would think about is the pistons, the KB's are hypers. If you're really looking at that kind of abuse, I'd think about going forged.

I'd also look at a higher capacity oil pan. The Milodon road race pan would be ideal, but something like the Kevko would also be a good improvement over stock. I have both, the Milodon road race pan is a beautiful piece, but costs every penny of it. The Kevko is a little rough looking, but is still a big improvement over a stock pan and doesn't hang down below the K member.