i'm running 3.1 right now just to be on the safe side until it warmer so i can have trannyman retuning it. hopefully i get full size ic before then so i can drop down to 2.9 pulley. my mods: xp, pp heads with L32 valves, 3.29 gear, zzp input, N* tb, ported inlet/outlet blower, ported lim, 42.5 injectors, cai, pacesetters, and 3" exhaust.