if you don't have to bore, don't...especially boosting the stock sleeves. a nice quick hone job to clean it up is all that is necessary. the power gain from .020 vs the holding potential of the stock sleeve is a push/shove relationship. you can run the turbo cams on an na motor- they have a good amount of lift, but just don't have the high-revving duration that all motor cams do- which is fine, its an ls. you aren't going to make power above 7000 anyway. buying 2 cams is a waste of time and cash IMO. GSR and ITR's have the same 4.40 final. only the JDM itr FDR is larger at 4.785. my thought is, just run a gsr. its plenty, and 5th won't kill you. tranny work is a bitch- and far from cheap. you're looking at a $3000 tranny the way you describe it.