I ran around for 10 plus years with 4.30 up front and 4.10 in rear. I never held it in 4x4 for long and only when slippery conditions were there like sand or ice and snow. I finally broke down for the 4.30 install of which I had to re pack the limited slip. I want a locker but am afraid for the rear as it is semi float. I was stupid and ordered semi when I ordered and bought the van, so it has c clips.Air only in the rear I guess.