Quote Originally Posted by Pher View Post
What don't you like about the 6.4s? I appreciate your input.

I have a friend with a 2500HD GMC but it's Gas and doesn't have the Allison Tranny. I've heard that the auto tranny has a lot of problems figuring out what gear to be in while driving. Either bogging down or revving out.
Wondering if that problem transfers over to all other 2500HDs too.
I would say ok to the 6.4 if you were going to buy a new one. First generations always have issues and the 6.4 is still a baby (and has issues, like flaming catalyst lol). I have no clue about the allison tranny issue though.