Im going to be doing the Ultimate TBI mods to my 91 RS tomorrow...Its stock with teh exception of an open element filter and msd 8.5 mm wires. Am i going to be runnine lean once im done with these mods or do i not have to worry about that since i have stock exhaust? Im just wondering if i should even bother with adjusting my fuel pressure...or if that can wait till i get new exhaust.

fuel pressure adjustments are mainly for very fine tuning. doing the mods will lean you out a little more than you are probably running stock, but... your computer can compensate for that and it will. Not really something you have to worry about. YET.

That what i thought. Thanks for verifying.