Not sure I understand what you mean by what kind,
@wjburken
As for year, I guess the newer the better. Just looking for something that can haul a good amount but is still good on the highway ride wise. Not looking for economy lol.
The 8.1L with 4.10's sounds like fun!
I had a 2003 Suburban 2500 with the 6.0L gas engine. I now have a 2010 GMC Yukon XL 2500 with the 6.0L gas engine. I thought the 2003 actually rode better than my 2010 - but that could have been because it had Michelin tires. The L96 6.0L gas engine in the 2010 has more power than the 6.0L that was in my 2003.
I never really paid much attention to the fuel economy in the 2003, but the 2010 does about 14mpg - with mostly highway miles. I tend to drive about 75 mph all the time though.
The 2003 truck was a definite rust bucket - so far - the 2010 seems better. There were a number of improvements in regards to rust mitigation on the 2010 that didn't exist in the 2003. The fuel lines, brake lines - etc - are all coated on the 2010. They weren't on the 2003 - and they ALL rusted out on my truck. A good part of the reason why I got rid of the 2003 - was that the thing had gotten to the point where it was either going to need a LOT of work to keep it from completely rusting out - so I decided to sell and get a truck from the next gen. I liked the 2007-2013 body style better anyway.
One thing the 2003 did better I think than the 2010 - was the the second row seats on the 2003 folded flat - they don't on the 2010. This made the 2003 a little bit better for hauling pieces of plywood than the 2010 is.
The frame and suspension on the 2003 and 2010 truck are pretty much EXACTLY the same. The frame carried over from the 2003 generation to the 2010 generation. So parts are somewhat interchangeable.
As somebody already mentioned in this thread - the GMT800 (2000-2006) trucks with the 8.1L engine - had a 12,000 pound tow rating. That means the frame is good for towing 12,000 pounds. The sticker on the door will not say 12,000 pounds unless you've got the 8.1L engine, but the frame is good for it.
I think this is important to keep in mind - because the hitches on the GMT800 and GMT900 trucks are barely good for the "normal" tow rating of 9900 pounds IMHO. If you look thru a number of the GM forums and some trailer towing forums - you're going to find people complaining about the factory hitch on the GMT800 trucks actually ripping off the truck. I swapped over hitch on my 2003 over to a 16k rated hitch. On my 2010 I built a custom 16K hitch for it - because nobody specifically made a "standard" style frame mount larger capacity hitch. ( the factory hitch is in the bumper reinforcement bar).
Why do I mention all of this? Because IMHO the tow ratings of the 2500 is cut back somewhat from it's true capabilities. As I said - the frame is good for 12K. If you look at a 2500 series pickup truck from say 2010, the trailering capacity of an crew cab/long box is 12,400 pounds - with the exact same drivetrain that is in the 2500 series SUV.
So my opinion is - based on looking at ALL of the various ratings of the different mechanicals with the 2007-2013 2500 Suburban/Yukon XL's - is that they're probably capable of towing 12,000 pounds.
The door sticker just doesn't say it. And therefore it wouldn't be "legal".
Depending on what state you live in - there's always the possibility of doing a diesel conversion. If you were ever going to think of doing that - I'd go for a GMT900 truck.
