Okay, I'm one of those that have a Granby on an old 1999 F-150, 1/2 ton 4x4 with the tail gate down. I bought the Granby new in 2005 and the truck new in 1999. First comment is I wish I had bought a 1999 3/4 F250 in the first place, but alas, at that time I was an active back packer/truck camper, and had no thoughts of buying a camper of any type.! But times change and by 2003-4, I was thinking about and actively looking for a pop-up camper. Soooo, you deal with what you got and go from there! As had been documented here on many threads the problems associated with the 1/2 ton/Granby combination(many of them mine) are numerous and the fix sometimes difficult! .
It took me several years of effort of trying everything to fix my reverse dump and bouncing badly truck. My ford dealer sent me to a local blacksmith who specialized in converting a 1/2 ton rear suspension into a 3/4 one and by far it was the best $500.00 I ever spent, No more things popping as I drove along a gravel road,no more pumping things up with air and measuring my air pressure all the time,no more buying super or reinforced springs, etc., My old truck cruses down the freeways now & gives me a fine back country ride and acts like a new truck. But guys, I sure wish I had bought a 3/4 ton in the first place!
Smoke