If you can find a 12 bolt rear out of a late 60s/early 70s Chevy pickup these are the right width and can be made to work with the AD springs without too much work. Plus you will get a large variety of gear ratios in the 12 bolts. I have a 3.07 and with the ratios in my T5 it works really well. The first 3 gears almost exactly the overall ratios GM engineers used with the 1/2 ton trucks and inline sixes and then 4th drops the rpms by 25% and fifth (.86) drops that another 14 percent which puts me just a little better than an overdrive 3 speed would have provided. The 12 bolt rear ends used in Chevy pickups (maybe also in GMC) were made for 6 lug wheels.

~ Jon
1952 1/2 ton with 1959 235 | T5 with 3.07 rear end