Not sure about the 2.5 but the 4.0s from 96-99 have 23# inj. and 99-01 have 22@ inj., which like Jeffy said, is a pretty good place to start along with an 8:1 FMU. Get the Vortec FMU you can buy recalibration kits for them if the 8:1 is too much or too little. I am experimenting with 25# inj. with a 12:1 FMU and so far its running great. I am taking it on a highway road trip this week and the first mountain I go up has a 6.5% grade for 25mi., should be a good test. As far as bypassing the fuel press. reg. at the tank, the regulator is on the exterior of the tank at the top of the fuel pump module and is removable, the fuel line connects to it. Go to a dealership and see if you can get a complete fuel module that has been replaced, or have a look at a new one to see what you need to do. It has already been done, some turbo guys have used a YJ fuel rail and press. reg. and ran a return line and somewhere I read about someone using the stock fuel rail, adding a press. reg. at the front and running a return line. However they did not elaborate on how they did it.
