This can't be a good idea. The question came up over the weekend about what was the best way to tow an old Wilderness 5'er with a T6H-5305. I don't think it can be done. The two ideas that came out of this here discussion was either to make a dolly with a 5th. wheel hitch, or to cut down the rear of the 5305 and build a hitch over the engine compartment. Now the 'man' says a dolly is another trailer, and 'ya can't tow no doubles in this state without special licenses an such. Is the arse end of a Fishbowl even strong enough to tow 5000#'s?
DO NOT cut up the back of of a GMC. The skin of the coach IS the structure. And you can't put an appreciable tongue load on a GMC, either, without overstressing the engine cradle and roof supports.
Besides, the 6v71 can barely get a 40' Fishbowl around, much less another RV hitched to the back.
So... yep... not a good idea.
If you do get it out on the road make sure to put the slow moving vehicle reflectors triangles on the rear
Larry Higuera