buyin a gsr and got some questions thanks

im lookin at a 97 gsr. its got 98k on the body and recently had a engine swap. the new engine has got 8k on it. the cars got a crazy list of mods like a zex nitrous kit, intake, headers back, valve springs, trans, radiator, ect. im worried about findin problems with it latter on. i was wondering if there are any pritty standard problems with tegs that i should know about or any things you think might go wrong with those mods. whatever you think let me know . thanks