The front of my 21' FW rides a bit high. I've adjusted the hitch as much as I can and can raise the pin box by 2" but haven't. Have 7-8" clearance at the bedrails as it stands. Is it worth the ha...
I am towing 1-2 inches nose high, with 6 inches of bed clearance. It is not worth the trouble, to raise the FW, in my case, but for you, with 8 inches bed clearance, I would raise the pin box, to make it level.