that doesnt tell me anything.

are you going to be driving mostly 70 on the interstate or 40 in the city?

 

there are really only 3 choices.

4.10's for highway

4.56's for city

4.88's for tires bigger than 35's if you upgrade later

take your pick.

 

I'll need 4.10's cause I mostly drive highway unless I'm offroading with it. Any I've tried to look this up but can someone explain what makes this different than whatever is currently on the rear axle.

 

Go with a Detroit trutrac. The install is about the same. Only much more streetable.

 

What's the difference between a trutrac and a locker?

 

True Trac is a clutchless limited slip and the locker is fully locked and not too friendly for street driving.
I'm running a True Trac in my Bronco and my '11 F150. I got the True Trac for my F150 on Ebay for $515 shipped.