I'm buying an 06 TG Unlimited shortly and just planning out the towing aspect of it for 2020 season. Boat sits on a triple axle aluminum I Beam trailer. My tow vehicle is a '17 Denali 2500HD Duramax.

Is a 39 with blower motors actually north of 11K pounds and that much heavier than a 38? Sorry for a stupid ass question but I'm just looking to math it out a bit and see how comfortable its likely to be with my 2500 truck with this boat on an aluminum trailer and a typical amount of fuel and gear etc in it.

Any feedback from others who are pulling 39's around all the time would be appreciated. Boat will be kept in my shop at home and towed everywhere, so its a big factor in my 2020 boat season plans.

You will be borderline and probably slightly over when fully loaded https://www.chevrolet.com/content/da...wing-guide.pdf

I've towed mine with two different 3/4 tons and have been fine. 14' GMC and 19' Ram. 1 long trip and lots of "around town" hauls and never an issue. Plenty of power and never feel unsafe. Even though I'm usually a madman behind the wheel I do leave some room to try to avoid any panic stops.

The Ram comes factory with airbags and does seem to pull a little better than the GMC. Both are fine though.

I assumed I'd need to at minimum add airbags to my Denali. Especially since I have a leveling kit up front which increases the issue with sag in the rear under heavy loads.

Would be around town stuff every weekend. (figure 50-100 miles each trip depending where) and numerous out of state trips planned as well (1k miles round trip or less)

My 38 on steel Manning trailer is closer to 12500 if I remember correctly- cat scales while hooked to 650 closer to 27000 total if I remember correctly. I have the slip in my truck Loaded w fuel. Would not think a 39 would be much different.
I was pulling it w my 3500 SRW CC and it did it fine --- BUT you pick what is better looking

I pulled the old heavy 38 Gun with a SRW 3500, then moved to a DRW 3500, both GMCs. Both did great, more stability in the DRW obviously, no tail wagging or getting pushed around during aggressive braking.

I would agree you will be borderline with the 2500, but should do an "OK" job. Move up to a 3500 if you can, or at a min install airbags. And I agree with the AOH brakes on all 6 wheels.

I will add, it is really more the trailer than the truck with what you have. You did not state what brand trailer? That really does make a difference. The higher end trailers are better balanced have better components and above all better brakes. At the very least, make sure your trailer is Electric over hydraulic, NOT surge. This way you can control the stopping pressure. If you have surge, convert it ASAP!

I wont get into the over-debated subject of "will it, will it not". I will, however, caution you from a liability standpoint and the insurance company's willingness to pay out. IF you do get into an incident and they find out you were over-weight for your rating, you may have trouble getting paid, and/or have a lawsuit if you injure someone. Usually it's the payload, or gross axle rating, and not the towing capacity that will get you. If you figure most 3/4 tons have a 2,000 lbs payload/tongue weight and ~10% of the trailers weight is tongue weight (1,200lbs from a 12,000lbs load), you've chewed through a lot of payload. Now add yourself, passengers, luggage, etc....you hit 800lbs, quickly. They will do the math, if there's a chance they can get out of paying...
Just another way to look at this subject, that's all.