OK I had asked this question once before, way back when, when this site was just an infant. I asked how I could tell if I have a LB7 or LLY. I was told to check the vin # and that it woule either have a 1 or a 2 as the first number or something like that. Anyhow that would tell me which motor I had. I determined through that process that I had an LLY. However, while tinkering under the hood I noticed that the manufacture date on my motor is 01/04. Thats January of 04, so is this still considered an 04.5 LLY even though it was only the first month of 04?

stupid question? you can always count on me):h

Probably a LLY but the 8th digit in the VIN is the key. 1=LB7 or 2=LLY

Yes they started building the LLY on Jan of 04. It is actually determined by the 8th digit of you VIN. 1 is LB7 2 is LLY

well vin says its an LLY and if they started making em in January then it looks like I got one of the first.
thanks guys

Actually I think they started building the motors in Dec. 03 so the trucks built in Jan 04 could have the LLY's installed. And yes, a Jan. 04 built truck is a 04.5. Half way through the model year that starts sometime around Sept the previous year, i.e., 04's came out Sept. 03.

Jim

one easy way to tell is look under the passenger side door.. if you see a HUGE catalytic converter then its an LLY. :-) If none..then LB7

Whats the difference between the two motors??

VR :)

A lot. The LLY is an emissions motor to meet Cal and NE emissions standards. The heads are diffrent and the LLY fuel injectors are easier to service. The LLY also is rated at more HP and Torque. It also has a variable displacement turbo charger with no waste gate. It also has a cat coverter

one easy way to tell is look under the passenger side door.. if you see a HUGE catalytic converter then its an LLY. :-) If none..then LB7

Unfortunately for me, that isn't always true. My '04 fed-emission LB7 was built in Sept 03, & it had a catalytic converter on it when I bought it. I still haven't figured out exactly why though, since I haven't heard of any other similar trucks with a cat, just California & N.E. emission trucks. :confused:

Unfortunately for me, that isn't always true. My '04 fed-emission LB7 was built in Sept 03, & it had a catalytic converter on it when I bought it. I still haven't figured out exactly why though, since I haven't heard of any other similar trucks with a cat, just California & N.E. emission trucks. :confused:
now THAT is strange.. do you also have EGR along with it??

If I recall correctly I read a post several months back on the 04 LB7's and LLY's sharing some of the same components, the CAT and newer water pump being a couple. JJ :)

thats crazy, I didn't know that. So the most definitive way is by the VIN# !!!

Noted.

A lot. The LLY is an emissions motor to meet Cal and NE emissions standards. The heads are diffrent and the LLY fuel injectors are easier to service. The LLY also is rated at more HP and Torque. It also has a variable displacement turbo charger with no waste gate. It also has a cat coverter
THanks man! :ro) I am a new to this info... ):h

VR :D

now THAT is strange.. do you also have EGR along with it??

Thankfully, no!

How do you know that you have no EGR? I would assume with the cat comes also the EGR

Open your glovebox door and read the options sticker (SPID). It's a white sticker with a bunch of numbers on it. They're in alphabetical order. If you have one or the other it'll be listed there. LLY or LB7. This is just another way to verify what version of Duramax you have, along with the VIN number mentioned in the earlier posts.