i have the timing set a 10 btdc, new wires ,new cap,new coil & spark plug. if i pull the #8 wire off of the dizzy theres no change in the idle? it idles a little rough and i don't think #8 it hitting. i did a compression check it's 145 psi, also readjusted both valves. it's a 1983 z28 with a 355 and 882 heads with stock cam. what should i check next?

 

Are you getting spark to the #8 plug? Might just need a simple tune-up. Cap, rotor, wires, and plugs. When you pulled the plug out to do the compression check what did it look like?