building a 383 have a couple questions

If ur engine hasn't been zero decked or is still original or has old replacement pistons, they are prob so far down u won't have a problem. Depends on your cam of course and you should always check p/v clearance. Any performance rebuild on your 383 u need to get the pistons zero decked or as close as possible to get ur compression up, and def check p/v clearance.