How to tell Between LLY and LBZ.

[Bowties4Life]

I'm looking at this 2006 chevy crewcab dually with
duramax it is used it only has 18,000 miles.
The sales man does not know crap about the truck.
He does not know if it has the LLY or the LBZ. It has the
six speed tranny but some of these trucks came with the
six speed but with the LLY still if i remember. I know awhile
back on this web site someone said you could tell be the vent numbers
witch it would be the last number. Does any body know what number
it is for the LBZ and the LLY. I have the vent numbers to check befor i
buy it just to be sure what it is. I would appreciate the help thanks.

[DmaxMaverick]

If it's an LLY, the 8th digit of the VIN will be a 2. You can also find the engine code on the RPO printout stuck to the inside of the glove box. It will have only one of the engine codes.

[Bowties4Life]

Thanks for the info i justed looked at the vent numbers
and the 8th numbers is a 2. LLY it is.