1973 Chevy Van engine is heating up

Hi buckaroux and TY for the donation

Check the radiator if its clogged-up if not perform the water pump test if okay -check the operation of the fan clutch if yours is one if every thing is okay so far, Try flushing the coolin systme and bleed the system thorougly.

Continues to overheat get it block and pressure tested to rule out the headgasket, cracked head or block.

One way to test for a bad water pump is to squeeze the upper radiator hose when the engine is hot and idling. Careful, because the hose will be HOT! If you do not feel much coolant circulating through the hose when you rev the engine, the pump may be bad. The other cause might be a bad thermostat that is not opening properly (remove and inspect the thermostat), or a clogged radiator.

Radiator clogged check feel across the front of the radiator for cool spot while engine is idling