The allison is the only combo available with the duramax

I would like to get a newer one, but honestly I HATE the new body style and really like this one. I ran the VIN on dieselplace.com and it cam back with all the info on the vehicle. It has a WD hitch from the factory - rated at 15k #...and it also has the Allison 5 sp tranny.

You too, Brian. Thanks for all the help man - much appreciated.
Brian has been helping me try to pick a good tow vehicle. While he was here I borrowed a 2003 GMC Suburban 2500 with the 8.1L gas motor and Brian met me at our shop where I keep the boat. We hooked the boat up to the Burban and tried to tow it around the block. Sure, it did it, but it was a pig....not to mention it felt dangerous as hell. Lots of frame flext under braking over bumps and uneven road surface not to mention maintianing 60mph on a hot day with any hills would have been horrible. Anyone considering a similar Suburban should know that there is no way it's going to tow much more than 10k #.
Hence my choice of the dually....

Well how fast do you want to tow? :D 16-18k pounds going down the road is a lot different than an empty truck. It's SUPPOSED to feel different.

I think the body style is the same from '03 to '06 and you're best off with the later years in that range.

The hitch itself isn't weight disstributing (WD). There's two tow ratings based on whether or not you are using a WD setup. A WD setup is a contraption that compensates for too heavy tongue weight. The truck can "pull" the weight, but the factory hitch can't "carry" the weight. I'm sure Brian has told you more than once you need to get one of these: http://cgi.ebay.com/Putnam-Class-V-H...QQcmdZViewItem

Interesting response. I am in the same boat and really want to get one of these duallies. However, the highest number I have heard with respect to non WD for a GMC 3500 is 7500 lbs and that limit is the truck and not the receiver. I would love to be proven wrong here. The Ford on the other hand states clearly 15000 lbs for a non WD hitch setup and in this case the hitch itself would be the limit.

Just about every dually 3500 I have looked at has the factory WD hitch and it says on the hitch - rated for 15,000lbs.

This is a weight distribution hitch:

http://aycu35.webshots.com/image/517...6407257_rs.jpg

And I don't want it on my boat trailer. Look what the limit is without a WD, the hitch can say whatever it wants, GM does not publish it to more than 7500lbs. With this set up (the WD hitch mounted to your boat trailer), the new GMC publish the limit to 13.000lbs.

This is accurate. I just went outside and looked on the hitch of my 2008 gmc 1 ton crew cab dually with the duramax /allison combo. 7500lbs wt carrying, 13000 wt distributing. if you want to be legal you have to go wt distributing. My 06 had putnam hitch products which are rated to 15 k on the ball part # 30012 for the ball mount rated for 15 k. You still wont be legal unless you go wt distributing though.

The only auto you can get with 6.6 is the allison. Only rear diff ration with the duramax is 3.73. Second gen engine had injectors outside valve cover, mutch better engine. You still can add power up features with minimal interference with emissions components. There towing specs are straight from GM.





Vehicle*
Axle Ratio
Maximum Trailer Weight
GCWR

6.6L V8 Diesel Dual Rear Wheel (Auto)
3.73
16,100 lbs. (7 302 kg)
23,500 lbs. (10 659 kg)

6.6L V8 Diesel Dual Rear Wheel (Manual)
3.73
14,600 lbs. (6 622 kg)
23,500 lbs. (10 659 kg)

Vehicle*
Axle Ratio
Maximum Trailer Weight
GCWR

K-3500 Crew Cab (4WD)*



6.6L V8 Diesel Single Rear Wheel (Auto)
3.73
14,900 lbs. (6 759 kg)
22,000 lbs. (9 979 kg)

6.6L V8 Diesel Single Rear Wheel (Manual)
3.73
14,900 lbs. (6 759 kg)
22,000 lbs. (9 979 kg)

6.6L V8 Diesel Dual Rear Wheel (Auto)
3.73
16,100 lbs. (7 302 kg)
23,500 lbs. (10 659 kg)

6.6L V8 Diesel Dual Rear Wheel (Manual)
3.73
14,600 lbs. (6 622 kg)
23,500 lbs. (10 659 kg)

Figures
 

Hey guys. Interesting conversation. The LLY engine came with either a 6sp man or the Allison 5sp trans. The manual was discontinued in mid 06 model year. Assuming you have a 4x2, the trucks rated at 9500lbs with a standard hitch,12,000lbs with a weight dist hitch, and 16,400lbs with a 5th wheel. The LLY was rated at 300hp and 520 lb-ft of torque. These are based on 06 figures which are the oldest I can find.
If you have the vin# I can get complete specs and some past service history as well.
Just to clarify, the published ratings on your hitch have nothing to do with the tow ratings on your actual truck. The truck could be rated at higher or lower ratings than what the hitch is rated for.