1978 1 ton shuts down when hot

Trying to figure out what going on with my old truck. When the engine (a 454) and eng. compartment heats up, it wants to shut down. So, depending on the outside temp and where I'm off too, depends on how far it will make it before it shuts down. Once I let it sit and cool off it will start right up, until it gets to hot again. Changed the carb twice, replace module (which was bad) and it's still being a pain. Anyone have this problem or a suggestion?:banghead: I am banging my head against the wall for sure.

My guess is fuel system vapor lock. Next time take the air cleaner off and look down the carb throat and work the throttle. See if any fuel is coming out of the squirters.

Does the truck have a two-line or three-line fuel pump?

Also check the coil. Swap one from another HEI or replace it with a new one.:2cents: