Wheels, Tires, Gears and Calculators
Sorry for the loooong post
I've been searching the TDR & web for 3 or 4 days (retired so that's a lot of hours) on tires, wheels, etc and found this nifty calculator posted by a TDR'er on another thread.
http://www.4lo.com/ Hope it helps answer tires, gears etc. ???
Also several TDR members noticed DC gives us a Heavy Duty Truck with a very limited selection of aftermarket light weight tires. My only choice to tow a ~15K/16K 5'er is the 3500 SRW HO Auto with 4. 10's. But the tires don't have the load capacity for the hitch weight. Most are under 3000lbs. max load, but the SRW GAWR is 6150lbs. (divided by 2 = 3075lb per tire). The OEM tires and one or two other tires at 3000 to about 3074lbs, but that doesn't leave much of a safety margin. Too bad DC didn't go to 17. 5" wheels. There are a lot more tires and they have higher load ratings.
The SRW and DRW have the same axle but the DRW has a GAWR of 9350lbs. because 4 tires are across the back.
I used the nifty calculator to decide on rear-end gears and tire sizes when I order our '03 3500 SRW HO Auto with 4. 10's. I will see if I can find 3400 lbs. max load 17" tires or go to 19. 5's with 245/70R19. 5. It will give me an effective rear end ratio of about 3. 99 and 265's will give me 3. 86. Sweetly inbetween the 3. 73 and 4. 10

for unloaded mileage and towing a 5'er. btw the load ranges for these 19. 5's depends on size and tire pressure. see this table for details
http://www.trucktires.com/library/technical/Loadinfl/table05.htm
Why not buy a dually? It won't fit in the garage, it has lower tow specs and it is too hard to take elk hunting.
Thanks TDR members for info on tires, wheels, gears and a whole lot more. Now I can get the best truck to tow a new 5'er.
Richard