Found a posi rear end off a 4x4,but will it work on a 2wd? its only $50,thats why im asking

 

It should. Is the junk truck the same year?

 

Are you taking just the diff or the whole axle? If it is the whole axle, then the axle width will be different (shorter on the 2wd). If it is just the diff, then you may need the gears as well unless you are going to be putting new gears into it. The diff may have a different series of gears depending on original gear ratio. You just have to be aware of that.

 

its $50 for the whole axle etc. How much shorter is it? i had plans of stubbing the axle and adding some wide tires so it wont exceed outside the body....

edit: and yes its the same year.

 

The 4wd axle is around 3" wider than the 2wd. I think actual axle width numbers have been posted somewhere.

The problem with swapping the axle is that you would have to run different rim offsets F/R if you wanted to keep your track width similar.