My first gen handled loads like that with the 33" tires/3. 54 gears quite well. I did have the pump tweaked pretty good though. You probably run as much power stock as my first gen did tweaked. Now with the larger injectors it just moves that much easier.
I have been running "D" BFGs for some time towing heavy. In my setup, they squirmed much less then the load range E stock michelins did. However I did not play with the "E" tire pressure much. With them at 80 psi the "E"'s squirmed pretty badly. With the "D"s at 50 psi same loads no squirm. I think the width of the tire had more to do with the stability.
This all being said, be sure everything, repeat EVERYTHING, is in top working order, tires pumped up hard on the rear, brakes in good shape, and the tires must be in good shape, like Nick said, NO JUNK. Don't get carried away, with that load it can get out of shape easily. You will have to find the proper placement of the tractor on the trailer. Too far forward and the truck will bottom out, too far back and the truck will bounce badly because of not enough weight on the truck. 6" to a foot for or aft will screw up the balance on my trailer when heavily loaded. Just practice and go easy!
My trailer wieghs about 7000# empty, and I have hauled several CAT backhoes and skidsteers on it with no problems. Just works the truck really nice.
Michael