I can tell you for positive that the 2015 Double Cab is different -- the older version of Torklift and Happi-jac do not fit without some modification. I spoke with Torklift and Happi-jac as well. Happi-jac says the old bumper bolt will work. I disagree, at least on my truck, I'd never use it that way.
The Lance dealer told me this plate is the new 2015 version. IF so, it's not correct, and needs some 'fixing'. It does not fit.
We just went through it yesterday - and had to modify the Happi-jac front mounting plate - although the plate worked, we had to flatten and re-bend it a bit. All the other older parts fit without modifying, although we had a hassle threading in the bolts and had to over-drill to line it up and thread thru the front plate.
We fabricated an entire new rear mount because the bumper mount will not work from Happi-jac as that bumper area is now plastic not metal. And that bumper pin is not a good idea anyway - IMO...
The hitch has a round brace / bracket beneath the hitch, as we fabricated a new set-up to slide right in it. If you want a photo, PM me your email and I'll show you what we built. It's very solid and sticks out a little next to the rear bumper, but believe me, that camper is going NO where with this one.
We might have gone "over-kill" on it, but carrying 3200+ pounds and my family, I'm sure gonna be safe and not "Wish I'd did it different." We mounted it and drilled it out, so it's secures with a hitch pin, and is easily mounted and dismounted - just pull the pin, or stick the pin back in it. It's built just like a hitch, only round.
SO, we modified the Happi-jac, built a new rear mount, and feel like this is a very safe set-up on the 2015 DC Chevy 4x4 2500HD ...
I'm not sure if the GM 1500 DC is the same set-up or different -- I'm certain the frame is different, obviously. But not sure if it's a 'bigger version' of the same frame -- and the hitch set-up might be the same on both trucks, not sure of that either. We only worked on a 2500HD ...
And I'm guessing most TC guys are hauling with a 2500HD anyway. Although some haul light campers with 1500's as well.
Monkey44
Cape Cod Ma & Central Fla
Chevy 2500HD 4x4 DC-SB
2008 Lance 845
Back-country camping fanatic