17 spline to 30 spline axle swap and posi problems

[66rat]

Heys guys,

I have a 66 c10, I believe it has a 63 or 64 rear end in it. What numbers would confirm this? It has 17 spline axles.

There is no fitment problems with the actual 30 spline axles themsevles, measurements between the 17 and 30 spline axles are the same. My problem comes in while trying to install a Powertrax Lockright.

Im trying to find out if there is a differnce between the differential case of the 17 spline yrs to the 30 spline yrs. I am about 3/16" shy of being able to install my c-clips on the axles with the 63/64 case I have now, even when i remove the thrust washers. Does any one know if the cases are different? Or is there something else in the rearend that would cause this difference in spacing? I know its not just a matter of shimming because it a have the same exact problem on both sides. I'm thinking that the surfaces that the side gears ride on are just a little closer together in this case compared to one that came with 30 spline axles. I assume that if it is a differnce in cases I could just get the correct case and problem sovled...? If so I will probbably just return the Powertrax and get a posi unit so I can eliminate the case issue all together, but either way I would still like to figure out the problem.

Any help would be awesome! If there is any more info I can give or if I can more clearly explain the dilemma, please let me know?

Thanks

[aerotruk63]

Don't know if this will help but it's interesting to read.

https://picasaweb.google.com/1138407...eat=directlink

[aerotruk63]

1Bad's contribution to the cause.

http://67-72chevytrucks.com/vboard/s...d.php?t=327764

[Captainfab]

I replied to your duplicate thread in the Engine and Drivetrain section.