I didn’t see one but I’ll look closer. I was actually looking for a pulley size but couldn’t find one.If that is a GM pulley, I would expect it to have a GM part number on it somewhere.
I have not. Great idea for something to look into. Since my pulley looks nothing like Rttoys I'm not so sure it was a GM S2 now, that is just what the guy I bought the donor from told me. There will be a bit more investigating into this. If the streets clear up a bit I'm going to see how the 3.0" pulley feels, maybe just an easy ride down the mountain and back up. When I started it last night and let it idle the AFR read 14.5-14.8.Have you compared your tune to a GM stage 2?