I have a 1985 F150 with the 300 six automatic trans. I have replaced the battery, starter, solenoid and wires to each. It will crank over with a good battery till it starts but the starter keeps going thus killing the battery. Any advice is appreciated

 

Sounds like a bad starter switch.
After the engine starts pull the ignition wire off of the solenoid (small terminal). If the starter stops then the ignition switch is probably bad or wiring is messed up.
If it keeps cranking with the ignition wire off then the solenoid is bad.

 

Found out its the cheap solenoids from Advance auto. Bought a better quality one from Autozone and starts right up.

 

I'd take the AZ one back and get a BWD LLW one from O'reilly's I know it is $25.99 but it is much better quality.