340 with edelbrock heads overheating

Read post #14 again. I spoke to a mechanic friend today with 40+ yrs experience who fitted Edel heads. [ Not a Mopar, but V8 ]. Nothing else was done, but temp increased 10*.

A new water pump may do nothing to fix the problem if the gap between the impeller blades & housing is large. It just churns up water but doesn't capture water. Same deal with high flow pump, it just churns up more water! The gap needs to be closed up so that pressure is increased to force the water through the restricted passages in the alum heads.