[1989GT]

I am going with at least a single turbo, but want to go twins. Mainly for bragging rights, you know how us car guys are. I know that if I end up with a single unit, I want to go with either a 70mm or 76mm T-4 unit. I'm not exactly a stranger to the turbo world, but I don't really understand the compressor maps. If someone on here understands them, please school me on them.

I would just go with a single 76mm, that'll take you were you want to go. Something like a .80ish AR should give you good street spool, although it may restrict you some up top, shouldn't be too bad though. The alternative would be something like .96 or 1.05 AR which might not spool until 4500-5000 or later.

I also need some advice on tranny. I know that I am going to go manual route, and TKO makes about the best unit on the market. The question is, will I be better off with 5 gears(track) or 6 gears(road)? I know that with some companies, like Jerico, you can custom order your gear ratios, but again, not that much of a gear head.

If you're against going auto, I would get a g-force t-5. I'm not a big fan of the new TKO's.

I am going to port the ever loving crap out of the heads, but for arguements sake, let's say I'm going with a stage 3 port job, with stage 3 cams. I will also be running a fully forged bottom end, main girdle, and so on. I fully expect to twist the rollers to the tune of about 650 or so

For this set up I would probably just save the $1000 on cams and put it someplace else. Plenty of cobra guys pushing 650+ to the wheels on stock cams. Also I think a main girdle is a complete waste of time on mod motors.
Sounds like a good starting plan. What are you planning on doing for suspension? Might as well go ahead a weld in the 10 point cage cause your gonna need it.