I have a 06 SS/SC with the GM stage 2 kit/ Tune with GMPP exhaust and GMPP sport cat back, ZZP 3inch catless down pipe. What is a safe Pulley size to drop down to?? Also what size is the GMPP stage 2 pulley?
Thanks for your help

 

I think most people say that a 2.9" is alright on the stage 2 tune. You obviously would get much better results by going with a custom tune though. IIRC the stage 2 pulley is 3.14"

 

why dont you look at this thread just started less than an hour ago?

https://www.cobaltss.net/forums/2-0l-lsj-performance-tech-47/problems-2-9-pulley-116424/

 

stage two is 3.06, stay there