The older 8.25's had a 27 spline but later 96 and all 97+ Cherokees had a 8.25 with 29 splines. The axles and carrier are beefier than the older 8.25

 

I just can't tell what kind of Rear end this is.... I've compared pictures and i THINK its a Dana 35..... Anyone know for sure?
('89 Jeep Cherokee Laredo)

 

That is a D35

 

What does 29 spline mean compared to 27 spline? Also what do you mean by the axles and carriers are beefier?

 

A 29 spline axle has more contact area than a 27 spline axle. The 29 spline axle has a bigger diameter than a 27 spline axle. The 29 spline carrier is physically different than the 27 spline carrier. You can upgrade a 27 spline housing to 29 spline as the tubes and diff is the same dimensions.

 

So would that mean that the 29 spline can more easily bigger tires compared to a 27 spline?

 

correct

 

So if I have a 98 sport, ill have 29 spline in my 8.25? Therefore shouldn't have a problem with 30's or 31's

 

no, you won't have any problems. With no locker the 8.25 is good for up to 35" tires (debatable) if you don't go too crazy.

 

So I keep getting different answers but now that everything is clarified, will mpg drop noticeably from 235's to 30's? What about 235's to 31's?

 

maybe a bit. You will have to account for the change in tire diameter when calculating your MPG though. Here's a good calculator for the effects of different tire sizes:
http://www.1010tires.com/TireSizeCal...?action=submit

 

Thanks for the link. Is there any rough estimate of what id lose mpg wise? Or do I just have to try it and then calculate it?

 

MPG will also appear to drop if the speedometer isn't calibrated for the larger tires. This is due to you going faster than the speedometer indicates which means it will turn the odometer slower.

 

What will the problems be if I want to take the automatic trans from a 94 Cherokee Sport and put it in a 91 YJ that is a 5 speed manual?
My biggest concern is how much of the electronic components will have to be changed.

 

What size of socket do I need to get my bumper mounts off? And what it a good way to brake them lose?