Which mod are you talking about? A new differential? The bushings? or what? I'll try to see what I can find.
Under step 20-22 or so in CHASSIS - DIFFERENTIAL - REAR DIFFERENTIALS, it'll show you a picture of what it is, but im still looking for a torque #.
Bingo, if you're talking about the differential bushing modification, then the bolt that goes through the bushings(T6) tightens to: 73.8 ft/lbs and the outside bolts(T2) tighten to: 24.3 ft/lbs. This was found in the CHASSIS - DIFFERENTIAL - REAR DIFFERENTIAL section under general description. Scroll down to the Rear Differential Mounting System. t6 and t2 are the bolts you're talking about.