Originally Posted by hemienvy
For big block, p/n 3698907, this is a single groove pulley, about 5-7/8 OD.

The pulley groove sits pretty far forward, it's "2 belt groove widths" farther forward than my 6-7/8 pulley.

Is this about the smallest diameter W/P pulley there is ?

Is there a pulley that is only sits one groove width forward ?
Or maybe a small diameter double groove pulley ?



I hope I'm figuring this correctly, but based on another post of yours about 7,000 rpm operation, wouldn't you need a bigger water pump pulley to slow down the water pump? Or use a smaller crank pulley? (But that would slow down the alternator too.)