The back side of the fuel pump can leak directly into the crankcase. If that is happening, it will be evident when you pull the pump. Try to preserve the metal fuel lines between the pump and carb. They sometimes get bent or twisted. They are much safer than the usual auto parts store rubber hose.

A failed needle and seat in the carb can also drain gas down the intake and past the rings.

Grinding into 1st and R is normal. These are non-synchro gears. You can, as suggested, hold the clutch a little longer before pushing into the gear. Or, you can just run the trans into 4th or 3rd or whatever your pattern makes easiest, then go directly into 1st or R. The engagement of one gear stops all the twirly bits from spinning in the trans, making engagement of 1st or R easier despite the lack of a synchro.

 

The fuel pump has a rubber diaphragm that cracks and leaks fuel via the lever that runs off the cam lobe and subsequently contaminates the lube oil.

Typical failure on a carbureted engine in the old days.

 

Anybody have an answer for why it runs good for 20-30 mins then decides to stall out and not want to start unless it sits for another 15 mins?

 

Could be your coil going bad. Next time it happens try this test;

 

Hi, I need help with my 68-76 dump vin

 

Welcome to FTE. Your question was answered in the other thread you posted in:

https://www.ford-trucks.com/forums/1...-decode-9.html