78 f-150 351m wont start after warm

My 351m will try to start after it gets warm.The engine turns over like the battery is almost dead.the solenoid hangs up and the starter will continue to rotate after the switch is off. I have replaced the solenoid but it continues to do this after it is warmed up.Any ideas??? engine has less than 5k miles on rebuild

1. Check the ignition timing, and make sure its not too far advanced. Also, look at the distributor's centrifugal-advance mechanism. Make sure the it is not rusty and moves freely. Sometimes, if it get stuck in the 'advanced' mode, hot starting can be difficult.

2. Consider a new starter. These starters are right beside the exhaust, so they get hot. When hot, the electrical resistance of the copper windings can increase, causing an excessive electrical load, slow cranking and a hanging soleniod.