I have an '08 jk rubi 4dr 4.5" lift and 37" bfg's. I was all set on having my dealer install 5.13's because they will warrenty labor for life but I read online it might be too much for the axles to handle. I want to get more power out of it cause its a daily driver. I do take it off road quite a bit and will be there as usual for the ejs in moab but I never bounce it. Will I be ok with 5.13 or should I go with 4.88?

 

So Far with RubyDoo about 8000 miles on the Yukon 5.13's and No problems what so ever.

 

With your 6-speed I'd be looking at 5.13's as a minimum and the 5.38's as even better. The 5.13's are perfect with my 35" tires. My RPM's at 70mph w/ 35's is 3,000rpm

 

X2-5.13s at least, 5.38 even better