Congrats on your new truck. We are just getting the pricing information on the new GM HD trucks this week up here. I am hoping to order my new truck soon.
I have a 2011 3500 HD Silverado and I believe the frame and drive train remained the same as the new 2015. I agree the body and bumper changed but my Torklift tie downs are mounted to the frame both front and back.
So I am hoping my 2011 Torklift tie downs will fit my new 2015 truck.
In 2011 I got my truck way before Torklift had seen the new 2011 trucks and I had to wait until they had to get my tie downs. But when they came they fit perfectly.
Hope you get your problem resolved soon.
Paul