I have driven all diesel pickups, and actually USED all of them. I Like the Duramax for its power (of course) reliability (thats the question) and quietness.
  I know there are different models of the Duramax, and some seem to have more frequent injector problems than others.
 Which model is best> Fuel mileage and reliability wise? And can someone tell me how to identify the seperate models, or are they year particular?
 Right now there is an '01 on the lot with 56k for $19,000. Or an '04 (less equipped) with 64K for $22,000.
  Any help is appreciated.  

right now trucks are not worth much like before remember that 01 is now 7 yrs old no matter the miles the bank will only go 5 yrs on a truck 5yrs are newer i would offer him much less and see if he bites from what i heard the 01 to 03 had injector issues they are expensive if you go back stock my buddys 01 has had 2 complete sets of factory injectors from the dealer installed under warranty. i would go for the 04 and offer him no more than 19  

If I had to choose any Dmax from its inception in 2001 to present, it would be the 2006 or classic 2007 LBZ. Reason is: the 2001 to 2004.5 LB7 had 300hp/~570trq and  injector issues. Not all of them, but a great deal of them. They all(auto) came w/5 spd Allisons up to 2006. The 2004.5 to 2006 LLY dmax was ok, but the HP/trq was 310/605 and the 5 spd auto always seemed to leave a little left to be desired when 3.73 gears(standard on all) and stock tires are used. The LBZ uses more efficient 6 hole injectors, faster spooling/upgraded turbo, faster 32 bit controller w/advanced fuel mapping, intake grid heater, bigger/efficient intake (atmospheric side), much stronger CP3 pump w/higher flow rates and that 6 speed tranny is stronger (internally operation wise) and drops your rpms by ~250 or so in 6th gear locked up. All of this equates to 360hp/650trq and better fuel economy. Granted, I have customers getting best fuel economy at up to 26mpg w/the LB7's but that is after some work and having the injectors replaced w/8 revised units. The 07.5-present LMM has more power (5hp) and the GMT900 platform but the emissions and fuel economy are not worth it. I have the LLY and the LBZ in 2 very different trucks. The LBZ is my favorite. pics @ myspace.com/richiestruckandauto  

I agree. I think the LBZ is the best. I'd avoid the LB7. There were some issues with that one. LLY is OK, but LBZ is the one to have if you can find one. LMM have the DPF, and will be harder to tune.  

I would also go with the 2005 4th quarter to 2007 first quarter LBZ as they have the 6 speed Alison and are a great platform for upgrades.

All LBZ motors have a D for the 8 digit vin.  LMM's have a 6.

Check out ebaymotors.com as the prices there are much more competitive and will give you some insight on cost.  

what are to look for when buying a duramax diesel  

KEEP looking you will find a better deal, People are giving diesel truck away now. Do your homework !!  

Thanks for the insite, the vin/years/model was very helpfull. Initally I was looking for towing and comfort.... however, the more I research, and the more I ask (never dumb) questions... I think I should look for a Cummins.
 My plans for my future diesel are daily commuting, towing frequently, and ease of maintenance-  meaning I have a shop/tools... my dad was a TV repair man (A little SNL humor for you)
 The Cummins (to me) is easier, not only, to upgrade but also work on. U-joints and suspension I can fix- no problem, it's a straight 6- no bells and whistles, no worries. On the other hand there is the Duramax- costly parts, crammed in, dealer "only" parts...
  I wont bash the Duramax, I liked my last one. But, now, I don't have my vehicle furnished by my employer... so I'm leaning toward a Dodge. From what I have researched they get beter MPG, are notorious for longevity and have only minor issues.  

Yeah. Cummins are the way to go for being straightforward and tough as nails. The GMs are nice & cushy and quiet, but Dodge probably makes the best workhorse. I think a lot of people's ideal truck would be a Super Duty with a Cummins. They specialize in that setup at <u>&lt;strong&gt;www.fordcummins.com&lt;/strong&gt;</u> and <u>&lt;strong&gt;www.destroked.com&lt;/strong&gt;</u>.  

This is just my opinion from performing high volume work on all 3 of the big manufactures. The Dmax is a pain to work on. But worth it though, I think. The Allison is VERY stout and the motor develops impressive HP. Dodge has quite a few transmission issues. They are weak and will definitely show their weakness once the engine is juiced up (if you plan to do so). This however, isnt anything that cant easily be corrected with the right aftermarket components and a few bucks. The Allison will on the other hand, take a condiserable amount of abuse, stock. The Cummins is a pleasure to work on compared to Ford or GM engines. There are currently, more aftermarket components available for the ISB than the Dmax or the Ford powerplants probably combined. The GM rides VERY smoothly, but is weak when large tires and torque are placed on them. Again, nothing the aftermarket hasn't addressed fairly well.  

The last couple of replies pretty much said it. I am aware of the trans issues on the Dodge, my last Duramax had the Allison and I cant fathom why other manufacturers arent at least trying to compete with it. A Cummins/Allison combo would be the absolute way to go... but thats not an option.
All of the replies are much appreciated. I'm in a position that I don't need to jump on anything immediatly, I plan on researching as much as I can, and asking a LOT of questions. So, your advice and opinions are greatly welcomed.
Please, feel free to offer any advice or opinions.
Thanks again.