I've sen 3" mentioned before. I've also seen some comments that some Fords had more frame flex than other trucks. My current truck (2000 K3500 crew cab long bed) has 2 1/8" between the center of the cab and the bottom of the camper overhang and hasn't hit in 20 years. But I only use a 1/4" thick rubber mat in the bed which minimizes the amount of camper bounce.
Truck manufacturers brag about how strong their frames are on new trucks, I just wonder if that translates into less flex between the bed and cab. I'd prefer to keep my center of gravity as low as possible and minimize the amount I have to raise the camper.
GM pickups have much less flex than a Ford, you can search frame flex videos and see the drastic difference. A standard rubber bed mat will also provide cushioning while helping hold the camper firm, the problem lies in many go cheap and heavy by using horse stall mats that are three times thicker and offer plenty of rocking potential. My setup is a standard rubber bed mat and an aluminum superstructure camper with minimal movement up top, but it still does move some.
Pre 2017, yes. For the last 8 years, no.
Fords were flexy until the 2017 Super Duty chassis. Before that they still had a c channel frame where Dodge and GM went fully boxed in the early 2000s new models.
I really wanted to make a GM truck work since they will let you get a gas engine in any trim line. The problem I ran into was the 2024 Truck-Camper Loading guide was completely wrong for the cab height. It showed the cab height as 40.8" but I just happened to measure the cab height when I was taking some other measurements and it turned out to be 44" and that didn't include the shark fin antenna. I'm glad I found out before it was sitting in my driveway although I could have dealt with it. The ram is 42.5" which was enough to sway me that direction (among some other things). Ford was higher than I even wanted to consider.
I'm hoping to be able to trim my current K3500 bed mat to fit the Ram. I'm also hoping that the Ram frame flex is low enough to let me get away without building a platform.
