What is the longest, heaviest, most tongue weight fifth wheel I can safely pull with my truck?

It's a Short Bed, Single.

Safely and legally are 2 different words.Safely Id say on the order of 2500lb lb tongue max,keep the rear axle under 6500 or so with singles unless you have a death wish or 19.5 commercial rims/tires. Lenthwise youll find most 30-34fters will have about that tongue weight. Since you have a crew cab truck your able to tow/carry a little less than most others.legally i bet your limited to a 1500 lb tongue weight,to keep your truck under the 9200 it grosses out at.I figure a loaded leather crew cab at 7300 easy.add your passengers/5wh hitch your up to almost 8000 easy.Leaving you not much legal pin weight.

My crew cab long bed weighs in at 7010 lbs with a full tank of full.

add another 600 lbs for humans and junk leaves about 1600 lbs. on a stock supension.

My guess is that the short beds weigh in about 250-350lbs less then mine due to less frame and bed.

John just about nailed it. You're looking at a max trailer weight of about 14,800 with a pin of less than 1900 lbs.

Now if you add air bags and keep your tires at max inflation, you can get a few hundred more on the King Pin. Your limiting component is the wheels and tires. You may be able to get more tire rating but the wheels are the show stopper. I think they are only rated for 3200 lbs each.

Your max combined weight, (manufacturer's rating), is 22,000 lbs. Subtract the weight of the truck, (7000+600 cargo), and you're looking at 14,400 lbs before mods to supension, wheels, and tires.

i have a 05 single axle crew cab short box and i pull a 36 foot fifth wheel with a 2nd trailer that is 18 feet with atvs all over wyoming and colardo. total lenght is about 70 feet and 26000lbs. i know this far exceeds the amount by gm. i have pulled heavy trailers all my life being as we own a landscaping company. im guessing there is about 3000lbs on the fifth wheel plate. i feel safe enough to do 75 all day long down the interstate and if theres no wind sometimes 80. as long as you do not have commercial plates you do not have to stop at weigh stations and they leave you along on the footage. i am thinking about adding airbags so there wont be any sagging in the rear. hope this helps a little.