i've had arb airlockers in the front and rear of my 03 GV. In 03 the ring gear changed size so I used the 3rd from a Vit/tracker. the axle splines are all the same on the GV/vits/trackers on the XL7 they are 27.
So you could grab a Vit\tracker 3rd and put the autolocker into that. and change your R/P's over to 5.125 front and rear if your a manual, this let you run 33's to get back to stock ratios

now the bad news, you'll need to be careful running the rear locker I started to play very hard and snapped 3 axles in 3 trips. everytime is snapped a had the cars weight on one wheel trying to drive up steep steps.