I picked up a 8.8 rear for dirty cheap. It has 3.73 gears in it. My stock axle ratio is 3.55. Will I kill stuff I run the front with the faster gears? (offroad only)

 

Until you regear the front to match the rear, you are 2wd ONLY. You use 4wd, you run the risk of breaking the transfer case, driveshafts and axles. Remove the front DS just incase you get tempted.

 

Yeah, unless you are in totally slick and sloppy mud when you shift into 4WD, you will break something.

 

Roger that

 

break and/or hop up and down pretty good

 

For mud some people prefer to run different gears. But if you go on anything hard even hill climbs you will brake stuff. So what do you use your XJ for?

 

trail riding mostly, light crawling.

I was thinking I'd swap axles and drive the truck until I can afford the regear, but I think that I'll just keep wheeling the Welded D-35 until it breaks or I can afford the regear. If I break the 35 it'll just be more motivation to get the 8.8 done and the front regeared

 

A lot of gears are mismatched front to back because of different manufacturers but not as drastic as yours at all. Such as a Ford with a 9" rear end with 3.55 gears and a Dana 44 front end with 3.50. Might have them backwards or the numbers wrong but it's close enough for you to get my drift I think. A lot of trucks are like that but you are talking about a lot more than that and I agree with the rest as it just won't work
clint