I have the Stage 2 JET module. It's an expensive paperweight. It only affects the truck at WOT, and you do have to run high octane, but the gains are minimal to point of being non existant. And the first one I got was defective right out of the box.

 

i see, ok well i got the truck and first thing i noticed is it doesnt have the lsd....sooo since its a daily driver i dont want a locker so lsd would probably be the best bet for me.... it is a 10 bolt rear end with 3.9 gears i think it said under the hood...steer me towards a lsd please

 

i've got a mopar performance computer and am still running regular 87 octane, i'm also running injectors off a mustang 5.0 H.O., if I run a higher octane there isn't a big enough difference for it to matter.