94 V8 mod, fuel pump prime only

carb engine for now, will TPI in future. I need to know what tells comp to run fuel pump or where pump relay is to rewire. Using mallory pressure regulator with return, just can't keep pump on.

relay should be in the relay box on the drivers side under the hood.

relay should be in the relay box on the drivers side under the hood.

There is no relay box under hood that I have found, one bank of 4 relays next to plenum box. Is there anything besides oil pressure that would prevent the pump form getting its power?