99redgtp

I have an 87 2door xj. I bought it off from a hack who scabbed it together but Ive got it going pretty good now. Its got an aw4 auto, a np231 t-case, dana 30 up front and it's got a non c-clip dana35 in the rear with 31s. So I was going to swap in a 8.25 that I have here bc I have a disk brake set up that I think will work besides it is a little bit stronger. I realize I should swap in a d-44 or an 8.8 but this is more of a daily driven jeep than a trail rig it might get run offroad a few times a year and thats just farm roads and such. Ive had it 2 years and havent broken an axle yet. So on to my question it still has the stock 3.55 gears in it and it wont hardly do 65 on the highway in OD it shifts up and down terrible. So I know it needs gears. I was thinking 4.10s bc that would put it back toward stock gearing. and it would be about 2200 at 65 according to randy's ring and pinion. I would like to go to 33s in the future idk how near of a future it will be but id like to sometime so 4.56s would be good for that. So should I just get the 4.56s now that way if i ever do go to 33s im set... I was just wondering I think the 4.56s with 31s will scream the motor to much on the highway but im not sure. thanx for any advice.

jpdocdave

if its a 4.0 and won't do 65 on the hwy with 31's something else is wrong. but to your question, i'd do the 4.56 off the bat, not a huge difference from 4.10's, and might as well go the extra step now.

here's a link to a post i wrote about someone interested in regearing, i'm just to lazy to retype some info on how its not a diy job for most people.

https://www.cherokeeforum.com/showpo...22&postcount=4

99redgtp

It will do 65 it will go like a raped ape if you give it enough time to get up to speed. The transmission hunts it if in OD it has zero power if in 3rd the motor will race like crazy and then upshift. It is old and wore out it popped the head gasket so i am doing a quicky re ring job on it to get it to stop blowing oil out the valve cover. It just dosent have the power while cruising it should have and I think its due to the gears I think I will go for the gusto and go right up to the 4.56s. thank you.

a1racer

like he said if you ever plan on going bigger then 31's don't wast your time with the 410s and the 8.25 will last with the 33's as long as you don't run it into walls and keep the gas on. but the 44 will be a big upgrade and the 8.8's are possibly a little stronger with some work to them