[LMH]

I think Chuck's correct that a gen pulley might slow the alt down too much, maybe to a point of discharge but a Deep Groove pulley is different. It's intent is to keep the belt in place during high RPM while still turning the alt fast enough. I'm just not sure if it would be the right size to make it look more like a gen pulley. They are usually around 3.5" to 4".
Larry