im in the market for a duramax and my price range is mostly the 01-03 models. My question is, do all the trucks with the duramax have an allison because some ads say they do but some don't and i wasnt sure if the allison was the standard trans with the duramax option. And the question only goes for the auto trans because I would like to get it with an auto. I'm moving up from a zr2 s10 so im pretty excited to get the full size.