GM-GMC: Chevy C-20 Stalls at Idle - Low Oil Pressure, oil pressure gauge, low oil pressure

Question
I have a chevy c-20, 1971, 350. When I first start the engine my oil pressure is fine, but after driving for a little bit the oil pressure drops suddenly when I put in the clutch. Then the truck stalls.

I sometimes have a problem starting the engine again, but after waiting a while for the engine to cool down I can start it up.

Answer
Do you have a mechanical or electric oil pressure gauge?

If it is electric, and is original equipment, it probably does not read correctly after 30+ years of use.  Buy a new mechanical gauge and install it.

A drop in oil pressure when loading an engine, such as depresing the clutch pedal, is normal.  Stalling is not normal.  What is the engine operating temperature?  A mechanical temperature gauge may show overheating and this will make the engine hard to restart.

Hot starting problems also result from worn out starters and/or poor battery connections.  Check all of the easy items first before changing the starter (and the solenoid).