School me on 6.6 L Duramax Vans

They seem to be unicorns.  I heard something too about these not having the Allisons and being detuned from the factory.

what years were they available?  Do they sell for a premium?  What should one be aware of?  I’m looking for GMC or Chevy in 4x2.  

IIRC, all the vans got the 4L85 instead of the Allison, and as a result of the lower torque rating of the tranny were detuned accordingly. That's about the extent of my knowledge, would love one as an adventure van though. I'm sure Curtis will be along shortly to school us all 

Yep, 4L80-variants. Perfect for that square body -burb swap I want to do. 

All I know is a YouTube family I follow has one to tow their 30' Airstream around all over the country (and Alaska) and it seems to do pretty well.  He had a travel quite a ways to get it since as mentioned, they are not common.  He's had to do a few repairs to it, but by most measures it gets pretty severe use. 

I'd personally be less concerned about the durability of a 4l80 than i am about intercooler packaging if you were trying to make it more powerful. Plenty of evidence on the internet of the torque-holding potential of a 4l80.  If you aren't trying to make it more powerful then the only thing I'd really want to have a handle on before purchase is the noise level in the cabin.

My friend had a couple for his irrigation company.  He dumped them after a couple years as they both seemed to go through the front suspension components very quickly due to the extra engine weight.  He didn't have any other reliability issues though.

i got a 2007 LMM Dmax 3500 Express van...it used to be an ambulance. I think its was Curtis that told me the 4L85 was in the Vans because GM didn't/couldn't change the floor pan/tunnel to fit the Allison.

The vans got less horsepower and torque. The 2007 to 2011 ones makes 250 horsepower and 460 lbs of torque. The 2011 to 2016 ones make 260 hp and 525 lbs of torque. The torque comes in at 1600 like the truck engines.

MotorsportsGordon said:

The vans got less horsepower and torque. The 2007 to 2011 ones makes 250 horsepower and 460 lbs of torque. The 2011 to 2016 ones make 260 hp and 525 lbs of torque. The torque comes in at 1600 like the truck engines.

Are those numbers just due to the factory tune or are they reflective of airflow constraints due to packaging?  Or both?

http://www.duramaxhub.com/lmm.html       250hp/460 lbft is true....secretly i was wondering how they could sell it with 200lb/ft of torque OVER the max limit of the trans they installed in it.

sad face... "de-tuning was common to commercial vehicles"  but it gets 17 mpg, so i cant complain

A 401 CJ said:

MotorsportsGordon said:

The vans got less horsepower and torque. The 2007 to 2011 ones makes 250 horsepower and 460 lbs of torque. The 2011 to 2016 ones make 260 hp and 525 lbs of torque. The torque comes in at 1600 like the truck engines.

Are those numbers just due to the factory tune or are they reflective of airflow constraints due to packaging?  Or both?

https://www.duramaxforum.com/forum/06-07-lbz-lly-duramax-powertrain/321233-van-vs-truck-duramax.html

found this just now I think it could be a combination of all of them plus the fact that the van probably didn’t need as much power as the trucks.

Seems like Ford's van tricks to me.  No intercooler, different turbo, etc etc.  

A 401 CJ said:

Seems like Ford's van tricks to me.  No intercooler, different turbo, etc etc.  

Probably for similar reasons - the difficulty of getting good air flow through a van engine bay compared to a conventional truck.