Welcome lincolnshome.
The dealers you spoke with were simply trying to make a sale, not providing you with the necessary info to
make an informed (& safe) decision.
You'll need a bit more info about your truck to determine the correct towing capacity, but this should help ---
Based on the details you posted & comparing the towing guides (links provided below), if I it read correctly:
AT BEST, you "may" have up to 10,500 lbs max towing capacity for a 5th wheel, but that's IF (& only if) your
truck has a standard bed/box and with the 4:10 rear axle ratio [plus the towing package, which you mentioned].
3:73 rear axle, and towing capacity drops to 8,500 -8,600 lbs max for a 5th wheel.
As already mentioned, the truck's load/payload capacity will also be a limiting factor. You can find that info
(for your specific truck) on the tire/load sticker on the driver's side door or door jam.
Trailering brochures typically show more detail for the truck configurations & towing limits.
http://www.gm.ca/media/vehicles/comm...rochure_EN.pdf (2007)
http://www.carlblackchevy.com/vehicl.../silverado.pdf
http://www.gmcertified.com/themes/de..._Silverado.pdf
Despite what those dealer's told you, the Mountaineer 347THT is NOT a good (nor safe) match for your truck...
it has an unloaded/shipping weight of approx 10,838 lbs, so the 'empty' 5th wheel weighs more than your 'at best'
possible towing capacity. Changing truck tires may help with towing stability, but tires do not increase the towing
limits as set by the truck manufacturer. Truth is, unfortunately, it's going to be very difficult to find a 5th wheel toy
hauler to match your current truck. Chances are, you'll probably have to choose a bumper-pull (toy hauler) if you
want to stay within your truck's limits.
Yes it's information overload, but don't stress -you're on the right track with asking questions & gathering the correct info
Good luck with your decision.
Terri, the Chevy co-pilot