I searched didnt see a direct answer, what gear ratio requires a new carrier to be installed also?

Background info: I have (wife has but someday I get it) 2010 rubi jku and when I get it, it will have 37's for now I plan to do the normal 2.5 TF BB and some 35 KM2's. In the end I want 3/4" long arm flat fenders and armor. So I only want to regear once, 5.38's seem to be what I am after.

So again would I need to change the carrier for this ratio or will the stock lockers and shit work?

 

You're good to go. A D30 with stock 3.21 gears is the only axle that needs the new carrier.

And on a side note - a three-quarter inch long arm? Really?

 

yup all .75 inches...! figured it wouldnt take long to catch that. 3 OR 4 inch long arm... leaning more toward the 4 tho. but it will be awhile still.