Posi Swap
 

There is a posi rear differential for sale near me. The ad says it's from a '72 chevy truck. My truck doesn't have the a posi differential. Is it possible to just swap out the internals into my differential or are the housings different? I am going to have the differential rebuilt by a local shop eventually and would like do the posi conversion as well. I'd also like to not have to swap the differentials I've just rebuilt the brakes, and painted it.

Re: Posi Swap
 

housings are the same, and it should just bolt right in.

Re: Posi Swap
 

Awesome, that's what I thought but figured I should check to make certain before I bought it.

Re: Posi Swap
 

Don't you still have to measure the backlash and all?

Re: Posi Swap
 

Opps, sorry thought you meant you were going to just pull the old and put it in your housing, lol. I jumped the gun on that one!

Re: Posi Swap
 

yes its not a matter of just ploping it in the typical measurements and clearances as per service manual should b followed to install and set the gears up

Re: Posi Swap
 

Just to clarify, it is possible to remove the posi unit from the donor differential, and properly install it into my housing? What about the ring and pinion? If my truck has a 3.43 gear and the donor has a 4.10 is it possible to use my 3.43 gear with the posi unit?

Re: Posi Swap
 

yes you can switch them you'll need new shims and crush sleeve etc.

Re: Posi Swap
 

If you currently have 3.42 gears and the Posi unit that you are looking at is made for 4.10s, you are out of luck.
The 3.42 gears will not work on a 4 series carrier. You would have to jump up to at least 3.73.
Either way you really need a Professional to do this install. It is very critical that it be done correctly....and it gets expensive when it's not done right.

Re: Posi Swap
 

I am definitely going to have a local shop do the work. I have already spoken to them about doing a rebuild. Hopefully it will be a rebuild with a posi swap!