Is this a fair radiator?

yellow rose said

You have a 6.75 inch water pump pulley. To get to 20% overdriven, you’ll need a crank pulley that is 5.40 in diameter

Click to expand...

If crank is 6.75 you would need a smaller dia WP pulley to spin it faster.

Or a larger dia crank pulley.


I would leave the crank pulley alone as it should be sized for the other accessories and just make the WP pulley smaller in dia to achieve a faster fan and pump speed.
5.5 to 6 would do it.

IIRC my 273 2bbl is 6.75 Crank And 6 WP stock but don't quote me.

Update, I tried to get some measurements crank seems to be about 6. 25, WP I can't get a good measurement