People are seriously retarded on this.
Judging from the door badges it SHOULD be an LLY truck.
The best way to tell what Duramax engine is using the vin # and count the 8th digit and if it is a
2=LLY used in 06 but now count to the 10th digit and if it is a 6 then you have the 2006 LLY .
D=LBZ
A 2006 with the old badges that say "Duramax Diesel", should be an LLY. If you have an 2006 that says "Duramax Allison" then you should have an LBZ. Notice I say should, not will be, with any mid-year change there are handfuls of trucks that got a mismatch on the line.
In 2006 they are the EXACT same motor LLY/LBZ just the factory tune in the ECM is different. Meaning: not different rods, not different pistons, not different heads, the 2006 LLY and LBZ are identical inside and out from everything I can find. So why the difference in tuning in 2006??? The LLY got a watered down tune because GM still offered the ZF6 6 speed manual with it, and the ZF6 is only factory rated for 610tq. In mid-2006 the ZF6 option was dropped and the tuning was upped to become what we now know as an LBZ, hence why the badge says "Allison" on them, because after midyear all Duramaxs were autos.
I currently own a 2006, and did the research, cross checked engine internal Part #'s, etc, etc. After hearing way too much confusion. My truck actually has the LLY vin, but came with the LBZ door badges, ECM had the LBZ tune. So with conflicting info I wanted to find out. And I had a co-worker that preached to me on my truck like he was an '06 expert, turns out he didnt know WTF he was talking about as do most of what these asshats on the boards are saying.
So to anyone on some hunt for only wanting an LBZ 2006, you're dumb and uninformed, unless you are scared to change the tune. Even though mine already had the LBZ tune, I used efiLive to roll it up from there.
LLY or LBZ who gives a ****, it will be the same truck with a tune change.
