I know that most when they drop pulleys get a shorter belt which is an okay solution but thought id do this write up as to save people some money and also get a better wrap on the supercharger pulley. I'm sure this has been written up Before but I have never seen it and I doubt that there was a listed part number.
so if you are running a 3.4 (that's the size I'm running) you can forsure run the stock sized belt and this pulley. This pulley, the pulley you will be swapping out is the tensioner pulley on the supercharger belt. The correct part number for over sized pulley is AUTOZONE/DURALAST #231081 if you don't want to get this at auto zone it is listed in there system as a 1990 c3500 7.4 with ac idlers pulley. This cost only 17$ which is much less then a new quality belt (gatorback or gates) This pulley is a stout steel pulley just like oem and fits perfect. The size quite a bit larger and take all slack out of the factory belt.
This is completely took care of any slip that I had on the supercharger pulley which got my boost back up to 9.5 lbs when I was seeing 8 at most before the upgrade/replacement of this pulley.
Will upload pictures when I get on the computer
also if admin sees this fit somewhere else please move it
