From what I've heard you need the headers and can open it up to 2.5". The SC will give you plenty of low-end. <img src="/forums/images/graemlins/butwiggle.gif" alt="" />
However if I wanted maximum grunt, I'd probably stay with 2.25" and the header. Brew <img src="/forums/images/graemlins/cheers.gif" alt="" />

p.s. - The only guy to do any dyno testing was William Gabay down in Louisville, KY. He bought my wheels and tires so I know he still checks the boards. Hey William, what do you think?

98 T100 SR5 4x4 3.4L auto, TRD Goodies, Bilsteins, engine/TC skids, 2" body/d.train lifts, F/R ARBs, 4.56 R&Ps, Aisin hubs, 255/85R16 Dunlop Rover RVXTs (street), 16x7 +8mm offset wheels, custom bumpers, Warn M8000, Master-pull synth. line