Quote:

I think what they require (I'll have to look again) is that the stud threads into the hex portion of the lug nut by at least the diameter of the stud. In other words a 1/2" diameter wheel stud would need to thread into the hex portion of the lug nut at least a 1/2".





Exactly

The reason for needing a 3" stud is to accommodate the thickness of the aftermarket disc brakes and the thickness of the hubs of the wheels used. A 3" stud is the only way to get the stud through that thick of a wheel to get the proper engagement in the nut.

If you use a stock drum and steel wheel chances are pretty good you'll have the proper engagement with the factory studs.