Well my 4l80 went out in my 03 2500 and before I drop the money on a brand new 4l80 tranny that i dont even like, could I put the allison from an 03 duramax onto my 6.0 vortec?
Would it be like putting the duramax in the suburbans like the duraburb man and just be expensive and time consuming and not worth it?

not worth it, you wont be able to tune it to shift higher then 4800. probably wouldn't communicate with your ecm at all anyways.

I wonder how much horse power and torque it would take to run the allison? I think my wife's 6.0 is rated at 380 ft lbs, my '01 Dmax is 520.

I think an Allison robs so much power it would be devastating to a stock 6.0 probably another 10% over an 80e

I considered this in my pop's 6.0 and did some theorycraft w/ Ben & others. You'd have to run an 8.1 tune among other things. Looks good on paper but not really worth it unless you had money to blow!

I have to agree with Smokin' the Ally may not be such a power rober to your 6.0 if it was blown and tweaked out but you would loose so much power to do it that it would be counter productive.

I'm interested in this also, anybody know what it would take to accomplish this? My 6.0l is blown and this would be in preparation to install the dmax into the sub.

I think the main reason for the body lift on the HD was for the size of the Allison. If you have a non HD, that probably is a dealbreaker right there. The 6L isn't a high torque engine, and the 4L80 can handle it well if built a little bit. The Allison is available with a stand alone controller, so you could probably integrate it if you reprogram the ECM as a stick.

Yea I agree, don't bother with an Allison in "prep for a Dmax as the specs on the 8.1 vs the Dmax are very different, just do it with the Dmax all at once from a donor truck. As a side note the Alison will fit in a stock body hight application, the lift is a "presence" thing as well as an accommodation for the Duramax application whose inter-cooler and radiator require it.

No point, the allison is way to much transmission for ANYTHING you can do with a 6.0. Hardly even suited for racing, only reason most duramax user build them up because there isn't much alternative. Its has slow shifts, has tie ups, torque management among other things. Only thing it was built for was high torque low reving trucks towing for the most part.