LA 360 piston ID

Have you measured the bore? Only .070" above the deck will not be enough to hit a stock open chamber head. They are generally in the .090" range deep on the side opposite the spark plug. If it's a 4.04 bore, somebody built a Hoover motor.

This^^^^. Don’t measure the dome. That’s screwing you up.

Only measure the quench pad of the piston, which is ABOVE the valve notches.

The you’ll know how far the piston is out of the deck. I’d be hoping like hell that piston is .070 out of the hole. That’s where it should be for an open chambered head.