valve clearance

[Bandit72]

when do i need to start worrying about valve clearance on a big block? i'm sure there are thousands of factors to consider but how about just a quick run down (if possible)

thanks

[Ghoste]

Not to sound trite, but anytime you change anything in the valvetrain or reciprocating assembly.  Altering camshaft timing events or changing to a thinner head gasket can bring them too close as well.

[Challenger340]

More info required;

What year/piston 440 ?

The reason is that Compression Distance of the Piston, varies with the engine year, or is it rebuilt, aftermarket Pistons ? Still require Comp. Dist., or "style" of the aftermarket Piston.

Stock, or "big" Valves ?

Any more pertinent info about the engine, heads, Pistons being used, would help immensely for you to get some valid responses.

What are you contemplating ?

[Steve P.]

Rule of thumb is .100 for the intake and .125 exhaust.