Won't start after its hot/warmed up.

[EN*PN78]

Well the weather has been nice in Portland. In fact its been hot out.
Problem is my truck will start in the morning, OK no problem but after I drive to work or park somewhere that is about 80 degrees outside my truck doesn't want to crank over with the turn of the key. I can run a screw driver over the starter solenoid contacts and she fires right up with the key turned on and in park. (old car trick) We have a new starter and solenoid. I moved the hot wires around the engine because I thought they where getting to hot, because they ran down the engine over the intake and exhaust manifolds (stupid anyways). I've checked all my wires on the starter and alternator cleaned my battery contacts. Its a automatic non tilt. Inline 250 six.
Is it my neutral safety switch? If I yank and bang the shifter into park it doesn't help either. Or try to start it in other positions on the shifting patterns.
Ignition bad, going bad? Thats my guess. Its been slowly getting worse.
Please Help
Thank You