So, I have a 8.25 29 spline rear end and 5" lift on 33's, should 4.56 gears be fine? and eventually should i go to a bigger rear end like a 8.8, im going to stick with 33's so i think i should be fine, My dad has a 8.8 we could put in but if the 8.25 will be ok then we can sell the 8.8 and get more money for lockers and gears.

 

Hey - I would use a calcualtor for gear ratio & tire sizes. Input the trans type etc. This takes all the guesswork out and keeps the engine happy running down the road etc.

http://www.ringpinion.com/Calculators.aspx

Tom

 

Yeah your 8.25 will be good up to 35's.
If this is your DD, then I would go with 4.56s. But if this a trail rig go with 4.88s

The 8.8 would be nice for the disk brakes, but if you are fine with your brakes now stick with the 8.25

 

Your 29 spline Chryco 8.25 with 4.56 gears is the perfect set up for running 33 inch tires.

If plan on running 35s or bigger, go ahead and start building the FoMoCo 8.8 that you have, as you can afford it. You'll want to re-gear it to 4.88 and most likely put a locker in it of some sort. No sense in putting tires larger than 31s on an XJ unless you plan to 4wheel it.

 

Thanks guys i think im gonna stick with the 8.25 and yes this is my DD and i am gonna wheel it. im planning on a locker eventually too.