Thanks Rich!

Does anybody know why the Duramax I have in my 05' 2500HD isn't offered in the 3/4 ton suburbans?

I'm told the engine fits in the chassis, but the allison does not....

The new Duramax/Allison combo will be available in the '07 900 platform Suburban/Yukon XL.

Russ is correct. It's the Allison that won't fit between the factory frame rails, and the M32 4Spd. Auto (4L85E) transmission offered behind the 6.0 and 8.1 Gas Engines in the Suburban/YukonXL/Denali/Escalade/H2/Avalanche is not stong enough to handle the torque of the Duramax.

http://www.duramaxsuburban.com/ will build you a Duramax Suburban though, but its not cheap. I looked into it for my 2500 Avalanche... briefly; VERY brief!

As an 07 model for Fall of 07? ... I would think that they would build the gas versions first with the HD to follow?

I can wait for late 07 if the DA and Ally are in the Sub

I have a 3/4t sub, with 4:10 gears and the 6.0L I love it. The gas mileage sucks, 11.3 to 12 on average.

Before you buy a 3/4 ton Suburban/Yukon for towing, check if the frame is one piece. If it is, like the 2000 I had, the frame will bend if you're rear ended and you'll end up having to replace it. The frame is over $7,500 and will total it after you add up all the labor. Pick-ups have repairable frames (they have weld points). Get a Duramax crew cab.

I special ordered my 2500HD with 6.0L and 4:10 gear. If I did it over now I would definately go 8.1L, Allison and 3:73 gear.
The mileage is hardly neglegible between the 6.0L and 8.1L but the power is tremendous.

The frame rails and floor pan are slightly different on the HD 2500 for the Allison. Other than that not much differnce.

The 8.1 gets about 11.5-12 mpg either 3.73 or 4.10 ratios.

Wannabe