the 04.5-05s are the least desired of all dmaxs. same computer system as lbz, just a smaller turbo outlet which increases egts and cylinder pressure, which, like said above, can pop head gaskets. there are much better deals out there, but maybe its an asking price, not selling price.
I have one of the so called least desired 04.5'. The turbo exhaust housing is larger on a LLY than a LBZ or LMM it spools a touch slower but has lower exhaust temps. The LLY uses a ECM & FICM to control the engine, LBZ & up only have a ECM no FICM Control.
To the OP. These trucks have very little issues when left stock however once ANYTHING is messed with the reliability can suffer but not always...
The early 01-02' engine had some head gasket issues, mostly due to injector failure & poor early CHIPS/TUNERS. GM/BOSCH have redesigned the injector and have fixed most of the trucks out there with warranty on the first series injectors. A simple vin check will tell you if they were done or not.
The LB7 01-04' engine had some injector issues, pretty much plan on injectors in those trucks every 75-100,000 miles & if you can't do them your self, flat rate is close to 12 hours if I remember correctly & each injector is about 375 bucks X 8. Injectors are under the valve cover on the early engines. The later engines LLY & up the injector is outside the valve cover, cuts the R&I time in half or more in some cases.
The turbo mouth piece is a big restriction & some believe is the cause of the high temps some of the LLY engines have been plagued with. I never had any over heat issues with mine in 55,000 miles but others have. It can be easily fixed as others have stated with a LBZ mouth piece or a AFE inlet.
Anywhoo the later trucks have the least issues in stock form, but also have more emissions stuff, LB7 non california has 0 emissions features, LLY-EGR & CAT, LBZ-EGR & CAT, LMM-EGR CAT & DPF, LML-EGR CAT DPF & UREA injection or (Cow Piss).
The allison can handle about 90-100 horse extra but you need to be nice to it in this range no full throttle take offs with a trailer or a bunch of 5th gear WOT runs.
If you have a good Diesel shop in your town I would recommend taking a perspective truck to them for inspection.
I bleed Duramax so if you have a question feel free to ask...
& yes the price is to high, 20-24,000 range is more realistic.
