Is there any difference at all between the 4 years the LB7 engine was put in these trucks? Or is it pretty much the same engine for 4 years. I am looking for specifics as well if you can get in to that. Thanks :)

I think they started using better headgaskets halfway through 02

I think they started using better headgaskets halfway through 02

Thanks, this type of information is what I'm looking for.

The headgaskets were improved mid year of 02, 03 also seen the oil pressure sending unit relocated as they went to a 3 wire one. Also in 01 the belt routing was different due to the pulley arrangement changing in 02, and 01 also has a one off intake that is different from 02-04. Also in 03 the wiring codes changed. I know there were some other changes as well that I can't think of right now.

The headgaskets were improved mid year of 02, 03 also seen the oil pressure sending unit relocated as they went to a 3 wire one. Also in 01 the belt routing was different due to the pulley arrangement changing in 02, and 01 also has a one off intake that is different from 02-04. Also in 03 the wiring codes changed. I know there were some other changes as well that I can't think of right now.

So nothing extremely different? Such as the Cummins on like a 12valve. The 96-98 Autos have 180hp while say that 96-98 5speeds have 215hp. Nothing like this?

No hp change.

Alot of off the shelve tuners wont be able to recalibrate the speedometer for different tires on the 2001 also.

Alot of off the shelve tuners wont be able to recalibrate the speedometer for different tires on the 2001 also.

Ooh, great info. Thank you

I know the up pipes from the manifold to the turbo are different on 01's than the other lb7's. Injectors seem to last longer in the 03-04 LB7's.

Injectors seem to last longer in the 03-04 LB7's.

I may not be the majority here, but I went thru two sets in 33k. The last set have lasted 45k now, but are getting noiser.

The 01 and 02's look wayyyy better. Haha just kidding.

In 03 the lb7 was put into the new body style:D:D:D

Just remember the lb7's are outdated and slow:D Thats why I went back to one;).

Interior leather is better in the 03+. :D The stock air intake box s different on the 01's, but can be modified to be basically the same as the 02+ by cutting out the 2 snorkels on the side. (Kennedy Airbox Mod) My 02 GMC gasser had the snorkels but was made in late 01. The 01 airboxes have let water in the box before and there was a TSB on it.

The 01's and some 02's don't have Cats. I might be mistaken on the years but my 2001 doesn't have a cat from the factory.

changed to better headgaskets too in mid 2002 from what I just recently found out

The electronics on the 01 and 02 are NOT compatible with the later engines. You can drop in (or close to it) a later version engine into an 03 or 04 with much less trouble.

The 01's and some 02's don't have Cats. I might be mistaken on the years but my 2001 doesn't have a cat from the factory.
The California/Federal/Fleet emission trucks do on all years. They also have egr systems. (Which suck!!!)

Yea, there are differences!! No EMISSIONS on 2001 and 2002. Had an 2001 Chev 3500 new on lease. It ran like a bat otta hell right off the lot. Got a Edge and very happy. In 2003 GM ran No Down No Interests deals. Decided I really didn't need a 3500. Decided to get a new 2500. Got it and it didn't run at all. Same specs on the books but something else must have been wrong. It wouldn't pull the same trailer up Sirocco Summit to the river. What I found was EGR and CAT first and stopped checking. I traded the new 2003 with 8700 miles in on a 2002 GMC with 37k. I never looked back n don't regret it one bit. That 2002 runs like hell without mods. My truck now has 5" Banks SS Exh. (NO CAT) Full ATS Tranny, Edge HOT Juice, PPE DuraMaximizer, PPE Boost Enhancer, Banks Big Head Waste Gate Controller, Banks Exh. Brake, and other mods including PROPANE Inj for knocking off those snotty nose punks in diapers who think they are tough enough with their hot rod Mustangs and whatever else they got...haven't lost one yet!! Truck has 87652 miles and pulls the 16,000lbs trailer up Sirocco Summit at 100mph!!! when needed. And the truck will ALWAYS be smog legal in every state! Hope my experience helps.

Only the cali emmissons trucks have egr and a cat in 03-04. My 03 didnt come with ether it is federal emmissons.