[Excaliber]

Engine noises (knocks and such) is one of the most difficult areas to diagnose.

A big clue here is: The noise goes away when the engine is warm. That could apply to piston slap. As the skirt expands it fits tighter, ie, to specs when warm. SOME, 350 Chevy engines have this "problem" as the engine was DESIGNED that way, it's not in itself "bad".

I am not aware that any standard Ford 302's had "designed" in piston slap. Race engines are often built "loose" and have it.

Main bearing(s) can also give this symptom, but less likely and a different (more "thud" to it) sound than a piston(s).

I'm not sure how the "cam" would exhibit these symptoms except for possible "lifter" noise, which is generally easy to diagnose as it has a distinct sound (assumes hydraulic lifters).

Ernie