[Chuck78]

I've got a '62 GMC 1000 Panel Truck with the Dana 44 rear end.
I'd like to upgrade to a Detroit TrueTrac or Nitro Helix torsen type limited slip differential when rebuilding the rear end.

I believe from referencing some old posts of mine that perhaps the 60-62 use a 10 spline axle? And 63-67 use a more common 30 spline? I see the old 10 splines are not common, and eventually 19 spline D44 axles were the standard and then 30 spline. I see mention of modern Jeep D44's being 32 spline even.

I know the carrier bearings are a concern with the old Dana 44's found in our trucks. I'm not sure if there is a difference in carrier bearing size between 60-62 and 63-67 or not. So wasn't sure if you could swap an entire carrier from a newer vehicle such as the aftermarkets that I mentioned, into ours with the correct size bearing, and what that bearing size might be.

Is it the carrier bearing o.d. or i.d. that's different, or both? I'd read mention years ago of someone using a more modern Dana 44 rebuild kit but having to machine a spacer to accommodate the different bearing size. So that would tell me that it is just the ID of the bearing that is larger on the newer models, or the OD of the carrier itself that slips into the bearing?

Is there a source for replacement / retro fit Dana 44 30 spline axles for our vehicles? Is there a difference in width or axle shaft lengths between the 60-62 and 63-67?

I've got a 2wd, so switching to a limited slip worm gear type torsen lockup diff will really help when traction is compromised pulling a trailer up steep gravel Forest Service mountain roads or in wet slippery grass. I got stuck with the one legger differential in wet grass once, it was quite embarrassing...
If my gears are worn and don't check out, I may switch from 3.07 to 3.31 ratio, with the intent of swapping an AX-15 overdrive 5 speed into it.

Thanks for the help!