[scottz]

I'm not sure. Contact Performance Trailer Braking and they can answer questions and set the install up if you decide to go forward. When I upgraded to disc brakes, I ordered the hubs with 9/16 studs and 9/16 lug nuts; my understanding is that is the difference between 7k (1/2" studs) and 8k (9/16" studs) axles.