But for what he wants the car for, custom isn’t practical for him. He wants a reliable daily driver WITH warranty that he’s not going to have to worry about.
Then ya kiss your warranty goodbye. GM will still honor the full powertrain warranty on Stage 2 IF you have the installation done by a GM dealership. If you don’t care about keeping the warranty, then you can install your own, have the dealer flash it, and call it a day. BUT…at that point why not just go a little further and go custom if warranty is irrelevant?
Yes and no. You can load either THE stage 2 tune or better yet a user-refined tune through HPTuners. If you don’t have HPT, then yeah, you can install pulley and injectors and just have them flash the tune on.