Because for all but the newest trucks, everybody is way over. It might be on a door sticker, but it should definitely be in the owner's manual. Until recently MAX GCWR was 16k lbs. Lately the factories have been uping the numbers to 20-22+k. I'd expect you'll find the difference with the later Allisons (for the GMs). The early ones I think were still limited to 16-18k. And the 4L80/85 is limited to 16k.

Biggest issue is stoppping not pulling. Make sure trailer has electric over hydraulic brakes and in cab digital controller. Had a 382 w/525's,gen on a very heavy steel trailer (3,500#s Pulled it from Dana Pt to Colorado with a 09 Dodge 2500 Cummins, pulled fine. Vail pass and Eisenhower pass are both over 10,500 feet. Exhaust brake on the Dodge helped tremendously You dont need a dually for that much weight Air bags are great help

Nort - It is GCWR, not GWCR.

2011 F350 SRW is 23,500# GCWR and 14,000# conventional towing with weight distribution hitch.

2011 F350 DRW is 30,000# GCWR with 3.73 gears and 33,000 GCWR with 4.30 gears, towing capacity is 17,500 conventional with weight distribution hitch.

https://www.fleet.ford.com/showroom/...ng%20Guide.pdf

I have never seen a boat trailer with weight distributing equipment on it. The max weight on the truck towing is 8,500 (same for the dually too)......see page 29 on that PDF.

Nort. I put WD on my last boat trailer. It worked just fine. I have since upgraded trucks and trailer, (same boat) and do not use the WD setup any longer.

What truck?

I just towed my 382 to the keys from San Diego with a 2012 F-350 DRW 2wd crew cab. Plenty of power, comfy, satellite everything, ****ty hitch.....I reinforced the hitch on my 06 long ago to stop it from flexing. I did not have time to do it on my 12.
The hitch flexes just enough to keep jolting you in the back! I have a LD hitch with bars setup with this trailer. It works really good but made the ride worse due to the flex. I unhooked it in texas and went the rest of the way without. In the keys I dropped the hitch and took it to the local weld shop to add some gussets. Oh 10.5 MPG towing, 19.5 without trailer.

Sandiego, to the keys? DAMN THATS a HAUL.

Correct. That is why so many upgrade to the Titan hitch.

http://www.drawtite-hitches.com/prod...er_Hitch,45297

Brian has a 99/01 (?) Ford 7.3L 4dr 8ft bed dually.