slant is running hot

the last annual inspection on ths car was 1981 so to the best of my knowledge it has been off the road for a really long time. i think the prev owner was trying to get it road worthy as it had a few new parts when i got it. will a heater core make a car overheat? with engine swaps i never bothered with stock rads just went right for the cheap aluminum ones. im thinking of pulling the top tank off and making something to clean all he tubes out. as for the water pump, i was thinking of pulling iot off to inspect it. think is possible the blades are gone?

Yes, a heater core can help with over heating. It is part of the system. If the water isnt flowing like it should, then the car will over heat.

Have the radiator rotted out. This will clean the insides out. Rust scale is usually what blocks a radiator up. If it has the org heater core, now would be a good time to replace it. check out www.rockauto.com for a price on one.

Always use distilled water, and I like to add water wetter. The stuff works.