Need help!

[Steviebinmiss]

Hi guys, i got an 83 gmc sierra and there is something i need help with. Ok, i can put the key in and turn the ignition on(you know where the red seat belt light comes on) but when i try to turn the truck on, nothing happens. i mean nothing. The battery is new (the lights work, dome light, brake light, etc.) so i know its not the batt. I hooked a push button to the starter to see if i could crank it like that. Well the motor will turn over, but there is no spark going to the plugs. i have replaced the ignition switch, the distributer, battery, plug wires, but it just refuses to start. I was wondering if anyone had a similar problem, and if so i need some advice. I think it might be a wiring problem? i would appreciate any help you could give. thanks.