my old gtp, when it had the 3.4 setup was on 3"fwi, 65# injectors, 255 fuel pump, 1.9rr, ls6 springs, 3" exhaust, and a custom tune by dyno brian, id say you would be ok, but would get a custom tune, the mail order tunes arent all that great imo.
Now, the new gtp i just got does have a scanner (aeroforce gauge) but is currently being shipped but should be here sometime between now and monday if you want to meet up sometime and just drive around, sadly i work weekends so its hard to get to the travk