Truck build out for

Not a Mammoth but it weights closer to 7000lb



The F550 handles it like nothing plus room to add tongue weight of a boat or trailer.
The ride is not good without the camper on so I ordered a Kelderman air ride suspension, but that will be another thread when it shows up.
The actual size of the truck is not much bigger than the 350 or 450 but what is underneath is what counts.
Good luck
Wes

If you were strictly hauling a camper full time, I could see doing the 550 for the ultimate in payload, duty cycle and stability, but aint noone wants to take an empty class 5 truck on a joyride, to the mall, down town, roadtrip on a bumpy freeway, parking garage, or god forbid down a trail!

The 450 is a compromise that at least still looks like a "normal"
pickup truck unless you're into the delivery truck/contractor/rancher look and has more than enough capability to haul any TC but can at least be set up to be somewhat civil when running bobtail.
The lower payload rating was explained above. It's fake. A 450 is more truck than a 350 all day and twice on Tuesdays!

Your current rig in that picture looks pretty new and capable. I'd have a hard time spending a bunch of extra money to upgrade unless that truck already has a pile of miles on it or you're planning on a Mammoth "plus" (plus big trailer, plus your whole life packed into a camper, etc).
Worst case, get a stout set of SD or Deaver springs fabbed up for the 350 and if you really want to go great gonzo, add 19.5s even though 18s will doo the trick and then some.

My opinion to consider....

Technically, the F450 has less payload because F450 is heavier due to a different front end and rearend and Ford caps the GVWR now at 14000 for the pickups. Once upon a time, there were people here who took F550s and added pickup beds. Others take the opportunity to add more storage with a utility body.

If you do some searches, you’ll see exacly what the other guys here with Mammoths use.

"this quite old man will slow and be happy to sit on a front porch..."

I'd rather sit under my TT awning!