Make sure you change out the ais motor and housing from your 2.5 on to the 4.0 throttle body. Other than that it is just a bolt on and an easy change. Get a gasket for $2 just in case your old one is shot. I noticed some change in high end performance (on the highway) and it seems to pull better in the lower end, too. My gas mileage went up by a couple of mpg, but I took the restrictors out of my air box and did a full tune up at the same time I changed out the TB.
Oh, I almost forgot... you will need a T20 tamper proof torx bit to change out the ais motor housing.