Really that would probably come down to an issue of not enough pinion and ring gear contact, with 4.88s only two teeth contact at any point (or so I'm told) and with 5.13s you'd have even less contact, also you'd be pushing a lot of torque so you would probably want or need chromoly shafts which means your gears would most likely be your weak point in the driveline, replacing gears is a lot harder and more expensive than u joints or shafts. Also it comes down to the philosophy of it, if you only use it as a street rig then 5.13s wouldn't be the best choice for rpms and fuel efficiency, but if you are using it off road you risk breaking an expensive gear set. But really its up to you

 

Actually, the new 5.13 gears that they're making for Dana 30's are designed to have the same amount of teeth contacting as 4.88s, so I'm told. With that being said, there are still horror stories of people breaking 4.88 pinions.

Unless it's strictly a woods rig then 5.13s will probably be too deep. I bought 4.56 over 4.88 because I daily mine.

 

dana 44s...not 30/35...rcvs & alloys


and it is used for daily driving, as well as mild off road duties, but the daily commute is less than 8 miles round trip, none of which is highway

sees less than 4k miles per year....most of which is below 45 mph



..

 

Man, 33s on stock gears suck *** bad enough... Can't even imagine 35s.

If you've ever driven an XJ on stock tires, you know how they're SUPPOSED to accelerate. 235s, still pretty good. 31s, not bad at all. 33s, still doable, but not great at all.

35s... Ugh.

 

What is this acceleration you speak of? Mine wasn't too quick on 215s when it was stock

 

Well that kind of information would have been useful in your original question

 

Well it's no Ferrari, lol. But a stock XJ will **** & git fairly well when you tell it to, assuming it's running right.

 

28/35 x 4.56 = 3.64
28/35 x 4.88 = 3.90

Choice is yours as you now have 3.73:1. With 4.56, you will regain some power back but will be at a higher ratio than 3.73.
With 4.88, you will have a little more due to it being slightly lower than 3.73:1.

 

thats what i run. i like it.

 

35s on 3.55s here, can it use more gearing yes and it will when new axles come, but it gets the job done.