the factory swing out, what size are you limited to? couldn't it be made to fit a big tire by spacing the mounting point out from the tailgate? and prolly beef up the backing inside the 1/4 panels?
lets see how you guys are toting a 38'' or larger spare, if you don't mind
Ahhhh no!
The "factory" swingouts are in fact aftermarket (Hickey and Valley industries), though dealers often sold them. Anyway, they WILL tear sheetmetal with a 33".
The good ones came with reinforcements for the quarters, but it's the vertical motion on the tailgate that kills you, or more accurately, rips the holes in the tailgate up.
If you sandwiched the tailgate (which would be tricky ... hmm, with the glass raised

) you could do a 33", but the extra weight of a 35"+ ... not gonna happen. One side of the tailgate just isn't a great structural mount.
Been there, done that. Now, on a pickup (i.e. no glass), you can weld a stud through to *both* sides of the tailgate, and then you have leverage on your side... I did this on my sixpack, and carry two gas cans back there (which is, err, something like 75+ #) and have no issue. The big difference is between a ~4" long stud held on both ends, and just sandwiching sheetmetal.
Anyway, HTH, and the point is, a real made-for-big-tires aftermarket carrier, mounted to the bumper or frame, is the only thing that'll hold big tires for long.
-- A