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**Boog** · 08-12-2010, 11:25 PM

The impellar looks correct in that pump to me.
So you've replaced the radiator, thermostat. What about the fan clutch and shroud? What about the state of tune of the engine itself? How does it run? Slow ignition timing causes one to run hotter than it should. A weak engine tends to run hotter. One other thought is the wrong water pump can cause one to overheat. You mentioned it. Earlier pumps turn opposite direction to later pumps. Are you using the instrument panel temp gauge only to determine how hot it is running? Possibility the temp sender unit in the head has been changed and it's the wrong one? It has to match the gauge in calibration. Maybe some of this helps.
Also a change from the 5 blade fan you have to a 7 blade can help.

08-12-2010, 11:25 PM	#2
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 12,957	Re: Water Pump Impellers & Overheating The impellar looks correct in that pump to me. So you've replaced the radiator, thermostat. What about the fan clutch and shroud? What about the state of tune of the engine itself? How does it run? Slow ignition timing causes one to run hotter than it should. A weak engine tends to run hotter. One other thought is the wrong water pump can cause one to overheat. You mentioned it. Earlier pumps turn opposite direction to later pumps. Are you using the instrument panel temp gauge only to determine how hot it is running? Possibility the temp sender unit in the head has been changed and it's the wrong one? It has to match the gauge in calibration. Maybe some of this helps. Also a change from the 5 blade fan you have to a 7 blade can help. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross Last edited by Boog; 08-12-2010 at 11:28 PM.