If that F350 is a dually, it should have close to 5000 pounds of payload. Our '06 F350 dually has over 4800 of payload.
EDIT: here's something to chew on in the thinking process. When setting up a high speed, heavy trailer, one reason I like trailers like GN horse and equipment trailers ( I have one each ) is you will notice these trailers have the axles nearly at the back of the trailer. This effectively forces you to "load heavy" in front of the axles, which makes for a very stable towing trailer at speed, and at speed, in windy conditions. A toy hauler like a Featherlite is built this way.
My GN 4 horse Titan tows exceptionally well in all conditions. Pin weight is your friend.
Without a doubt if I were setting up another race trailer, it would be a GN. With a BW turnover ball ( what we have ), the bed of the truck is converted to an empty flat bed in seconds.
