butters49 wrote:
I am pretty unfamiliar with truck campers and how excess length affects the suspension of the truck. So any help would be appreciated!
There's no general "rule of thumb." There are shortbed compatible campers, long bed only compatible campers and those tht will work for both.
The longest ones that are SB compatible are close to 9' long. And some can be loaded with the tailgate on, some cant due to the design of the rear overhang.
One thing is for certain, ditch the headache rack if it will require you to raise or move the camper aft.
I'd suggest looking at a bunch of shortbed campers dimensions and configurations. It will help you understand.
Of course there are always some more obscure exceptions, but we're talking good practice and proper application.