What gears should I run for a 1990 xj with 3" lift and 3" body lift, and 33" tires? and Where can I get them? How easy is it to put them in?  

I would get 4.56's as you have a AX15 tranny with a .78 OD and this will give you 5 fully usable speeds. With 4.10's it will labor at times in OD and not be fully usable. When you lift it is more than just doing math on ratios because lift and tires add more drag too so you need more gear than you think for it to run good. Installing them is not for faint of heart but if you are good with tools and can follow instructions it is doable. As for source, I have gotten a several new gears off Ebay in last few years as a some vendors sell there.  

Thanks Snoman  

has anyone ever used 4:27 gears in there TJ with dana 44s the reason im asking is that when i compared them to 4:88 i was told that if i change to 4:27 i will not lose 5 th gear and i would save money in fuel cost because im not at a higher rpm , i have a inline 6 with the edge computer chip ,and running 35 inch tires right now i have 4:88 and my engine as no more pick up as a stock engine thats why i added the edge chip, . i dont take off in fist gear because low, please if some one could help let me know thanks  

you'll get worse mileage with the 4.27's and will hardly get to use 5th with 35's  ya need the 4.56-4.88's with 35's to come close to stock performance.

the 4.56 will turn 2250 @65mph  

Yes, I do not know why some seemed convinced that the best way to get good MPG with a lift is taller gears and lugging motor a bit. From a 4.88 to a 4.27 is a big jump and it will have a big negative impact on OD performance, a loss in over all performance and maybe even a loss of MPG too. You are going to loose some MPG with a lift due to increased drag and rolling resistance from lift and you are not going to get it back with taller gears. You have about best possible combo now 35's. Do not mess with success.  

3" body lift on an xj?  

fordtech46310:
3" body lift on an xj?

they'll figure it out.. LOL  

I saw the body lift too?? unibody vehicle with a body lift??? how's that work?  

96cherokee:
I saw the body lift too?? unibody vehicle with a body lift??? how's that work?

Its not possible. It is wrongly called a body lift. You could bolt new bracket to were suspension attaches to unibody and lift it but that is not really a body lift.