I was told that a 30 foot fifth wheel was the absolute max for any half ton pickup, and a few would be overtaxed as far as braking and curving roads were concerned, regardless of what the vehicle weight labels say; as I am sure you probably know, the "pull" is only pat of whole equasion. My Tundra is rated for 7,200 +/-, and it doesn't like anything much over that; it will pull a lot more, but stopping and going around corners are a whole other thing. I understand the HD versions of the big three's half tons are closer to a three quarter ton, and can handle the extra weight, but in reality, a three quarter or one ton is the deal for towing of any significant weight. I had Chevy "work" trucks in the 70s and 80s that I hauled tool trailers and shop trailers with; the three quarter tons would reliably handle trailer on frame hitch that scaled at ten thousand pounds, and the dually 3500 would tow up to twenty thousand, but it was getting a bit chancy in mountains.

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