rear end swap?
 

Im looking to swap out my stock rear end for one with positive traction. It needs to be six lug. I've heard that the 73-87 Blazer would be a good canidate? What have you guys used that works for these trucks? thanks.

Re: rear end swap?
 

The differential from any K10 thru '87 as well as the '69-'87 K5 Blazer would be of the 6 lug variety. I'm not too sure just what they measure though compared to the '63-'70 12 bolts. As long as your current 12 bolt has the 30 spline axles, you can install a 'posi' carrier from any truck 12 bolt. Which were available thru '79 and some early 1980 models.

Swapping the entire differential from a K series can be done, but you will need to change the mounting pads if your truck has coils. Plus you will need to either transfer a panhard mount from a '63 or '64 12 bolt, or fabricate your own panhard mount

You can also go with an aftermarket 'posi' or locker.

Re: rear end swap?
 

the vast majority or 60-66 truck had posi's.

why swap out the entire axle when all you have to do is the carrier.

Re: rear end swap?
 

It seems hard to find a posi unit for the 63 & earlier rear ends, I've seen alot for 65' and up. Any body know where to look ??? thanks

Re: rear end swap?
 

the reason you would have to swap the whole axle is because 63-64 have 17 spline alxes, while most posi's are 30.