No spark at the plugs.?

I have a 93 Chevy c1500 4.3L v6. I was driving it the other day and it just quit on me, it will turn over fine when I try to start it but, I found out there isn't any spark at the plugs, I replaced the Ignition coil and Module, and the distributor cap and rotor look to be in good shape, I'm puzzled on what else it could be... Any idea's?