Common

Because I'm researching them...

My next truck will be a Dodge or Chevy...

I'm skipping the 98.5 to 02 Cummins and the LB7...

It comes down to price and warranty...

I want a 3500 also...

This is in the next year or so - keeping the 12V...

I love the Cummins, but the fact that my Cummins service center can't even troubleshoot the CR with their diagnostic tool is absurd. And I hate the dealership...

Which brings me back to the warranty...

If I can get a 5 year on the GMC, that might be the route I go...

I'll NEVER own a Ford...

EVER...

If it was given to me I'd trade it or sell it...

LOGAN

LBZ in the 2006 and 2007 classic trucks, they are 360/650, make sure it is an LBZ and not a "new model" LLY, they only came with the 6 speed manual in 2006 and the LLY and 6 speed manual arent available in 2007 and newer trucks, they are just low horsepower LBZ's, the brand new trucks are the LMM with 365/660. best bet is the 2006-2007 truck with an LBZ, they can take alot of power, have the 6 speed manumatic allison and i think they look better than the new trucks, my cousin has a 1/2 ton crewcab new chevy and the interior sucks along with the space in them.

2001-2004.5= LB7 decent motor with some drawbacks, 5 sp allison or 6 sp manual, 300/520

2004.5-2005= LLY first generation, advanced LB7 design, prone to overheat, needs LB7 intake and turbo to make work right, 5 sp allison or 6 sp manual, 310/590

2006 only= LBZ and LLY "second generation", LLY is just a detuned LBZ, both share everything but computer programming, both have bigger main bearings, stronger block, and better piston design than previous LLY and LB7, 6 sp allison manumatic or 6 sp manual only available with LLY, 360/650 for LBZ, 310/590 for LLY

2007-2007.5 classis= LBZ from previous model year, 6 sp allison manumatic, 360/650

2007.5-newer= LMM, its an LBZ with 5 more horsepower and some Gov. Emmissions quirks thrown in, 6 sp allison manumatic, 365/660


this is just what i know about the trucks, i thought i would list the stuff so it would be easier to read.

turbo dreams

i thought the 07's were the llm's or lmm's? i would own a lbz in a heartbeat. i just HATE ifs trucks!!!

LOGAN

they are LMM's, i should of put that in there but didnt, they are just LBZ's with 5 horse and emissions crap on them. fixed it.

udflyer98

The LMM is in the new body style 07.5 trucks. It's possible to get a "classic" Silverado/Sierra 07 with the LBZ. One correction to the numbers posted by Logan - the manual trucks are rated 300/520 regardless of engine or model year. I'm not sure why GM recycled the LLY model designation in 06 after substantially beefing up the bottom end of the engine and fixing the cooling issues. To answer the original question, get an 06 or 07 truck if you go with a Duramax. Unless you can find an 01-04.5 LB7 truck with updated injectors. These are a little easier to mod and no cat to fool with on the exhaust.

johnny5.9

The injectors weren't the problem on the lbz but rather the pressed in sleeve that they sat in. The sleeve had an o-ring on it to seal it to the head. With vibration and time the sleeve would loosen breaking the seal and allowing fuel to leak. Because of their location under the valve cover they would dilute the crankcase oil. That is my understanding.

johnny5.9

I was not aware of any "second generation" LLY. According to sources I read the host of improvements to bottom end including new lower compression pistons, new main bearing, new connecting rods cam on the LBZ not the LLY. The LBZ is new in many ways and is hands down the best generation of d-max yet. Sure the new LMM is the same engine with marginally more power but it's also saddled with new "e-quipment" that will definitely hold it back in terms of bombing and longevity.

LOGAN

all 6 speed manual trucks in 2006 were designated LLY, cause they were "low output" compared to the "high output" LBZ, my friend Rob had one and traded for a better equipped 2006 LBZ with the manumatic 6 speed allison, the truck i always talk about pulling. the LLY from 2004.5 to the end of the 2005 model year is a engine all in its own, its a screwed up LB7, not the best engine really, compared to the engines that came before and after, the 2006 LLY is just a detuned LBZ, they had to have a detuned motor cause the flywheels in the 6 speed trucks couldnt handle the power, that is why you cant get a 6 speed manual anymore after 2006.

the LBZ has better block, pistons, rods, CP3, bearings, pretty much everything that makes it what it is. a main bearing for a LB7 and a early LLY cost 9 bucks a piece, new model LLY and LBZ main bearings cost almost 100 bucks a piece, they are almost twice as wide. block is stronger, pistons are coated on the sides and have lower compression, CP3 flows 10% more.

alot of the truck pulling guys try and build hot duramax motors with stock parts, it dont last very long, just save the money and put the 3500 dollar pistons and 2800 dollar connecting rods in the motor and be done with it on the first shot.

thebestofindica

07 classic.

Grit Dog

Don't count out the LB7's.
Althought theyare known to have injector problems, the 01-03 models are covered under warranty (injectors only) for 7yr/200k mi. An 02 or 03 will have 2-3 yrs left on the warranty.
Although my truck only has 63,xxx miles now, the engine has been flawless. Actually the whole truck has been repair free except for a NSBU switch that went out (known problem, $70 part).
LB7's are the mos fuel efficient of the bunch and even though underpowered compared to the new LBZ/LMM, a 60hp tune or program puts them right up w/ the new ones power wise. I run mine constantly on 60-90hp program and it doesn't slip the trans at all.
LBZ is nice b/c of the 6sp Alli, lower rpms on the highway, but doesn't do any better than the LB7 on fuel. I've clocked fuel mileage form Albq to Denver several times and running 80-85mph in my truck, it still gets 18.5-19mpg.
LLY's the early ones had overheating problems. 06LLY's are the same as an LBZ, w/ less hp. No overheating problems reported w/ them.

tony597fitter

Plain and simple

NONE!!!!!!!!!!

xOmertAx

i've gotta say 02 from personal experience.

01smoker

From what I've heard if I was in the market for a duramax it would definetely be a 06.5 or a 07 classic. Those have the LBZ's in them. The previous two motors had its flaws but the LBZ's have them worked out and have very little or no flaws in them yet. They are beefed up internally and you get that 6-speed allison behind them.

I traded in my 01 Cummins for a 04.5 GMC Duramax last year and I liked it but you can see what I drive now below.

PoorMansCat

I'd stay away from the LB7 engine, unless you're a "tuner" and don't mind wrenching on it... They have some serious issues that GM will admit to, and they also admit there is no good fix for it. The extra 100,000 injector warranty is ok, but what about resultant damage from injector failures???...
We are having better luck out of the 06-07 D-Max trucks, but from where we were with the 03's, anything has been an improvement.

adamrc

2006-2007 LBZ... Lots of power and very reliable.