Hi all, I am new here. I am putting in an order in the next few days for a 2021 Sierra 3500 AT4. I plan to pull a 5th wheel with it so I want to maximize it's payload capacity. It seems that the long bed has a bit more capacity (weight wise) than the short bed. Can somebody explain why? It makes no sense to me as it has the same suspension parts and is 16 inches shorter (thus lighter) which in my mind translates into more payload capacity for short bed (the opposite of published numbers). I would prefer to buy the short bed just for parking convenience, but am planning long for the benefit of payload. A scientific answer to my question would be greatly appreciated, and if you can show me that my gut feeling is correct, I will quickly switch to short bed. Thanks.