I have a 88 and 90. There are no real tips really, other than read/research/plan. Tons of info in here and there are other Supra forums on the net with a lot of technical info is needed.
Prior to doing anything, ask what people think about that one specific question. (easier to get info that way)
Very hard to advise someone on what they should do without knowing:
a. what thier goal is
b. what their approximate budget is
c. what their base car is
not sure if that helps.. but it might start a conversation
btw.. this is the show and tell area.. so pictures please
If you have a technical question (about the fuel being rich), put it in the MKIII technical area (scroll down in the main form area)