1972 C10 Cheyenne

[GeorgiaCountryBoy]

Hello!,
I have a 1972 C10 Cheyenne Long Bed with the V8 350 CID engine. I am having trouble starting it after it has been running for a little while. It starts up fine for the initial start and if I drive it around and then park for say 5-10 mins and come back to try and restart it I am having an issue with restart. It sounds like the starter is hard to turn. I have replaced the starter, solenoid, starting coil and the battery is holding a charge just fine. If I wait 30 mins and come back it will start right back up again with no issues.

I am a information security geek as my day trade and I have a mechanical engineering background but I am far from being a decent mechanic! I can read schematics and troubleshoot via google so you wont hurt my feelings if I have done something wrong or I am missing something silly! I really appreciate this forum because it has really helped me with this old truck! Thanks in advance for your help!