Yeah u can sell it later if u decide to pulley down any smaller, I run gm stage 2 with bolt ons and a custom tune and its pretty quick but I'm about to swap in some 80s injectors and a 2.7 pulley then have my tuner give me an e85 tune because I want more but u will enjoy the stage 2 for a lil while and then down the road if u want a lil more power u can get a custom tune for ur setup. Most stg 2 cars with everything else stock put down around 235 to the wheels that I've seen from the dyno section, also consider doing the air box mod if u don't wanna buy a cold air intake(they is a how to section that should have a write for that) it's cheap like 40ish bucks vs a good intake like zzp that's around 200. Also I'd consider rotated tranny mount to reduce wheel hop some, Ottp, Powell, ttr and zzp make them very nice item. Also don't forget to check ur ic pump to make sure it's working before u add anymore mods to ur car.

 

If you install GM STGII yourself it's safe to drive to the dealership for the reflash.

You may get a MIl/CEL with code P0172 before the reflash though.

I ran a stock tune on 42# injectors a month or so before I got it tuned up right.