Just my opinion though.

 

AWD NVG-149 = 2203 ft. lbs rated Max Capacity Torque
Auto-Trac NVG-246 = 2281 ft. lbs rated Max Capacity Torque
Manual Shift NVG-261 = 2563 ft. lbs rated Max Capacity Torque
Auto-Trac 3/4, 1 Ton NVG-263HD = 5430 ft. lbs Max Capacity Torque
Manul Shift 3/4, 1 Ton NVG-261HD = 5430 ft. lbs Max Capacity Torque

The front differentials are both 8.25" assemblies and the only difference is the AWD units have a one-piece passenger side axle. All in all, the front diff from the AWD may be slightly stronger due to the one-piece axle, while the Auto-Trac is rated the stronger of the two transfer-cases. I believe if I already had the AWD transfer case, I would stay with it. If I had an Auto-Trac case and wanted something stronger, then definitely the NVG-263HD would be a great upgrade.

 

is the 3/4 ton tcase a direct swap for the 1/2 ton?

I dont suspect it to be, but it would be a nice upgrade.

I have a floor shift fwiw...

 

Electronic wise would the Auto-Trac 3/4, 1 Ton NVG-263HD be a direct swap for the Auto-Trac NVG-246 ?

 

At a minimum the NVG-263HD is designed to go behind at least a 4L80E. So without an input gear change, it wouldn't connect up to a 4L60E. It would be an excellent opertunity to jump into an 80E though.