well i havent got to fix any of the mentiond items yet but a MAJOR help to the smoke issue was replacing the cap and rotor along with a new coil. ill be replacing the O2s soon
i believe the MAF is in good condition.
but when i had the exhaust off this past week to replace my 4l60e (in which i lost both 3 and 4th gears) i could visably see that the o2 had a pretty good coating of 'soot'\so im sure thoes were my issue most likely

 

Black Smoke doesn't always mean too much fuel. Black smoke can be caused not enough air too. check your air filter. just because it looks clean doesnt mean its always clean. at wide open throttle your sucking alot of air. but if your getting enought air than its def. over fueling. just hope its not blue smoke!