edelbrock 1406, running way rich, how do i tune them?

All of the above.

What sort of cam do you run?

Are you sure the carb is clean, not all gummed up inside?

Has someone before you (used carb?) been "into" the thing diddling with the metering rods and jets?

You might have "junk" in one or both needles, causing fuel to leak past. Can you hold the throttle at some RPM, and look down the carb throat? Do you hear or see fuel siphoning over into the throat? This makes an erratic popping sound sort of like bacon frying.

Too high fuel pressure

Floats damaged

Floats set too high

Needle/ seats damaged/ dirty

Carb is dirty/ gummed up, metering rods stuck

Carb has been "effed with" by previous owner