I have a 96 Jeep Cherokee XJ and I just installed a 3.5" lift kit. It has a dana 30 in front and dana 35 in the rear with 3.55 gear ratio and I put on 31x10.5x15 tires. Do you think it could be hard on the transmission and engine accepting those gears or do you think I need to upgrade to different gear ratio. I found a matched pair out of a 90 or 91 jeep Cherokee with ??? 3.88 or 4.10 that I haven't seen yet, will these fit in my 96 Cherokee if I get them. They are a dana 44. Do you think they will fit and do you know if they came with ABS brakes back then.

31s and 3.55 gears aren't a bad combination. Your Dana 35 rear axle is the weak link, I would start looking for a Chrysler 8.25 to swap in, a Dana 44 out of an XJ would be good too but they are hard to find.

The XJ (I have a 96) wants to get into over-drive (4th) pretty early. Meaning it can shift to 4th as early as 38-40 mph. Probably not that big of a pain on the original 225 tires. But even on my 30s this can be a bit frustrating when I'm in rolling hills. Being in over-drive (4th) with rpm in the 1300-1400 range will really feel like it is robbing your power, and your gas mileage will suffer as well. Your 31s will accentuate this even more. So in those regimes I typically use the drive gear (3rd, or 3 on the shifter). Then I manually shift to OD when the RPMs and driving conditions allow for it (after the hills, back on the flats, or downhills, and the RPMs getting above about 2300rpm). Basically, if you can't keep 1800+ rpm in over-drive, you might as well downshift to 3rd. As an added benefit, on the AW4 you get transmission braking in 3rd gear, but you don't in over-drive. So in 3rd you don't have to ride the brakes as much when decelerating.