So I picked up some 20" factory wheels that came off of a 2015 2500.
two issues. The lugnuts are metric so I'll need new closed end 9/16" nuts.
Also If I turn to full wheel lock the inside of the tire rubs a little so I'll need wheel spacers. Anyone done this? Thinking 1/4 spacer will work?
Does anyone know what the proper cone seat taper for these rims?

 

Most likely rubbing on plastic inside the fender unless you see rub marks on the control arm.Are the tires not the factory 20in size? could be the reason if they are bigger.

 

285/60/20
Yep there are rub marks on the control arm. Only rubs when the wheel is fully turned in either direction.