i already have a duel ALT pully on my S4 T2, would i be able to use this on A S6 ALT?

 

Short answer, NO. However, (dreaded word usually) you can drill out the center section if you are careful enough. Probably should take it to a metal shop and have them do it. The reason being is the shaft on a FD alt is larger. I have heard most people buy a late model GM alt pully for the alternator. Just take the alternator into a parts store and they should be able to figure it out. Hope this helps.

Curtis