I'm getting bigger tires for my 2wd truck and was looking into getting a locker so I could have some fun in the mud and when I ran the search I found very limited information on lockers. I did come across these Detroit lockers with don't seem to lock your wheels while turning and goes back to full lock with you give it the gas. I wanted to know what other mods I would have to do in order place this product on my truck, and does anyone know how much they cost? Would I have to regear my truck? Everything is stock on my truck the sticker with all the things that came with it says "2007 F-150 4x2 Supercab" "Optional Equipment...3.55 Ratio Regular Axle"

Edit: Will it void warranty?

 

In the simplest of terms:

A LS has packs of clutches to keep the two wheels turning when you lose traction. It does slip.

A locker has one of several methods of mechanically locking the axles together when under power.

Powertrax has a lock right that drops in your open diff by replacing the spider gears. I believe that nearly anyone could install one.
Edit: The E-Z locker seems to be the same way. Remove the spider gears and install the locker.

If you install a traditional locker or LS, you would have to re-set the ring and pinion clearances as the carrier would be replaced. One that replaces your spider gears, no.

It may void certain pieces of the ring and pinion warranty because you have a third party shop tinker with it (or you), but it wont void the whole rear housing. They have to prove that the part caused the failure, not the other way around.

 

You're going to have a lot more slack in your drivetrain, or backlash. When you put your truck into park your truck will roll about twice as far as it does now. Or when you're getting on the gas it's going to take longer to put the power to the wheels. It's just a minor annoyance, but it's worth the offroad capability. If I were to get a locker right now this (the powertrax no-slip) would be it because I know I can install it. The EZ-Locker appears to be very similar.