You don't want it.. it's a waste. The chip for the 4.0L causes more problems then you'd be interested in.

I've read that those who have put the chip on the 4.0L have seen whopping gains of 2-4hp at the crank.. you won't even notice anything at the wheels, and on top of that you have to run premium grade fuel.

Chances are the 2-4 hp gain is from cleaner injectors from upping to premium.

Just get intake and maybe get an exhaust setup.. you'll get more for your money with those two then you will from the 'chip'.

EDIT: Jet Performance is the company that makes the 4.0L Stage 1 and Stage 2 chip.