New wheels won't clear hubs

I ordered some new Billet Specialties Legend Rival rims for my 74 Dart Sport
15 x 10 with a 6" bs on the rear which fit great on the Dana 60.
The fronts are 15 x 7 with a 4.75 bs and they won't fit over the hub.
The rims have a 3" hole in the center at the back of the rim but taper to about 2.75" starting about 1/2" from the rear towards the front side of that hole and the hub outside diameter is about 2.86"
The other problem is the stock studs are only 1" long and are not long enough for the conical nuts to be safe. I have no problem changing out the studs.
I was hoping I could find a replacement hub and rotor assembly which has a smaller outside diameter hub if something like that is even available?
The wheels cannot be turned down inside so my only other option if I can't find a smaller hub is to have my hubs turned down about 0.16".
Selling these rims is not an option.
Does anyone know if a smaller hub/rotor is available?
Any other ideas?

Thanks