Water pump pulley?

[Ironmike]

I remember reading here, years ago that for maximum cooling, your W pump pulley should be smaller than your crank pulley. Sounds right to me so where can ya find a pulley under 6 1/2 inch diameter?

Checked all the usual suspects and they're all 6.5 to 6.7.

 

[Dana67Dart]

The 67 273 standard cooling is under driven the wp pulley is about 6.75 and the crank pulley is about 6.5

If you can get a 6.5 and your crank is 6.5 you will probably be fine

The other thing that was done is fewer vanes on the water pump, when the speed was increased.

Check your FSM, I recall there are over / under drive specs in the cooling section

 

[Ironmike]

Thanks, Dana!