I guess this might be a stupid question, but is (or should I say was, as I am looking at a 2003) the Allison standard when you get the Duramax? If not, in 2003 what transmission was automatic was standard and is it any good? Seems like most if not all folks post that they have the Allison or the manual, but the Allison is listed as available on the GM site (perhaps that means available vs. a manual).

Thanks,

Yes with the exception of the new Vans and Hummers I believe.All the Silverado's with the Duramax get the Allisons.

Option with the 8.1

Yes with the exception of the new Vans and Hummers I believe.All the Silverado's with the Duramax get the Allisons.

Option with the 8.1

Option only over a manual, so same as the diesel.

This probably doesn't matter in this post, but I jsut had to correct it:D

Actually, the Hummer H1 Alphas come standard with the 6.6L Duramax and the Allison.

For the pick-ups, the ZF 6-speed manual is the standard transmission (but they're rare) for both the 6.6L Duramax and the 8.1L Vortec. The Allison automatic is an option for both but I'd say 95% of these trucks are built with one.

However, the Duramax's HP and torque for ZF- 6 speeds is limited to 300/520 ft-lbs. If you want the more powerful diesel version you have to get the Allison.

Thanks guys!