1981 Chevy 1500 Doesn't Fire!!!

I have a '81 Chevy 1/2 ton that i can't get to fire. I have already changed the Ignition Module, and the Coil. I pulled the number on plug and still got no fire!!:banghead: ! I need help! Any suggedtions?!!?

Check the dist cap and rotor for carbon tracking. Check timing. Check plug wires. Check for spark out of coil. Check for signal to the coil while cranking.