Rear End

[TCCliff]

I have a 85 1/2 ton chevy rear end with 3:42 gears and posi-lock, I wanted to know if I could take the posi-lock out and put it into a newer chevy rear end, like 90's or 2000's. Any help would be great, thanks.  

[VileZambonie]

You can put in whatever you'd like, just make sure your u-joints and brakes are compatible.

[Blazin]

Do you mean the carrier, or the whole rearend? The whole rearend is not going to be a bolt in as the spring perches are spaced diferent. Also not sure if they are the same overall width.
As far as the carrier I am not sure about 1/2 tons. I used the carrier out of a 04 rearend for my 86 3/4 ton semi floater.

[TCCliff]

No just the carrier (internals), I'm pretty sure the 85' has a 12 bolt under it.   You said your 3/4 ton could interchange with a 2004, is that the newest you can interchange or could you keep going up to 2007?     And does anyone else know if a 1/2 ton will work? THANKS

[roundedline]

If you '85 now has a 12 bolt it won't be the same as the 10bolt in the 99-up trucks.  I believe the 8.5 stuff will swap, but I cannot say 100%.  

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[BILTUP]

8.5 stuff will swap except the newer one uses 30 spline and the old ones are 28 spline.