what yr on the 318 block?

is it a roller cam block?

are those aftermarket pistons?

need to know how far down the hole the piston sits,so mock up the crank and 1 piston to get a start

if you go solid on the cam you will need adjustable rockers/push rods for the head you will use

dont for get oil isssues if you go mag heads on the older LA blck