With JUST a pulley...no...now your talking supporting mods...I could consider a IC and a 3.0" with exhaust work and injectors supporting mods and put 100 more horse to it. See what I'm saying? With all of the basic mods with a 3.8" and then swapping to a 3.4" you'd see around 20 or so to the tire with the right tune...not 40.