ok, ok. it was a bad idea. I didn't really want to spend the time trying to make it fit. It was a last resort kind of idea. I'm going to look for some after market pulleys.
So where did the v-belt pulleys come from? I had no problem using my old original pulleys on my 5.0 (which BTW I'm not using anymore).
I looked the pulleys up on johnsmustang.com which happens to be local here. They sell water pump pulleys in various depths. So I measured how much more I needed, and went and looked at what he had in stock and got one that fit. Still needed minor shimming, but I mean like using a set of four thin washers, and they lined up.
The rpms are of minor importance, the pulley grooves lining up are the most important thing. You can play around with the diameter to over or underdrive the pump to vary the coolant volume, just as you can with the impeller size. And in changing pulley size you can change the fan speed.