Need Help With Carb

[somery]

I am having a bad carb problem. it burns extremely rich. i have the primary plug out and have adjusted it completly (i think) i have everything cut down to a minimum without it affecting power loss. it still smells strong. i have cut the black smoke down to a minimum, but its super rich still. i heard something in chevy hi performance magazine saying something about a blown power valve. is this me? what does that do? i have a 4 barrel Quadrajet (E4ME) electric mixture solenoid and choke; vacuum ports. the choke works good and stuff, but the carb runs rich at idle and still kinda badly goes from idle to off-idle. can't peel out without it seeming like it would hurt it too much. ive pretty recently had the heads redone cause of the blown head gasket, timing chain and oil pan gasket replaced. the crankshaft looked clean and good. didn't pull the camshaft out. also a quick question about plugs--if they foul out from rich conditions and i clean them to looking pretty again, are they good as new (as they look) or are they still considered fouled. they were pretty black.