Axle help

[Daniel Steele]

I want to put a locker in my sport trac, and i would also like the change the gear ratio to a lower gear for offroad. Can someone give me some links to both of these and what gear should I choose. Keep in mind i still want to be able to drive it on the street too.

 

[Patrick Wallach]

What size tires do you plan on running? The general thought I've seen is for 32-33" run 4.56 gears but 4.10s will work well. 3.73s will be pushing it. Personally I run 35s with 4.10s and it wasn't terrible for me but it was slow off the line. For 31s I think 4.10s would be a great ratio on and off road. Sorry I really don't know much about lockers.