Overheating 360 new engine

The SMALL water pump pulley is for FASTER fan speed and impeller speed. Kind of what is needed with a 6 vane impeller. To slow them down you go larger pump pulley or smaller crank pulley....

Back when I use to get the DC newsletters and Magizenes, I think Larry Shepard said the 8 vane cost like 4-5 HP on a 340 and 360 but the consensus was on a street car or truck it was worth it.

Gain 5 HP is great for bragging rights. Lose 5 HP but gain more cooling is better in my book.