Not gonna tell you what to do, just what I do. I have the same truck as you, only a ’16, it is completely stock. When I scale it, the weight is 8,000 lbs empty….it has been scaled numerous times and always close to the same. If I remember right the sticker on my camper says it’s around 2,500 lbs. When I scale with the camper on and loaded ready to go, I am at 12,000…..done that several times too and it has always been within a few hundred pounds. In the past I have pulled an enclosed trailer with a car in it from Alaska to America and back. Never did weigh the trailer deal. The truck has handled the loads flawlessly.
2016 3500 HD Durmax
1994 S and S 9.5' Camper (SOLD)
1999 S and S 9.5 Camper