I am looking into buying a 1994 Supra TT. When recently looking at a Bomex body kit, I noticed that there were different parts for a "JZA-80" before and a "JZA-80" after. I have no idea what this means. Any information would help. Also, in my research, I have read about different engine models. Is that just Japanese vs. American or are there different American models. Thanks for the help. I dont want to buy the "wrong one" if there is such a thing.