• Off-Grid Overland

Project Duramax

Updated: Nov 19, 2020

Here is the truck we will be building over the next few months.


2004 GMC 2500HD, LB7 with an Allison transmission. This truck has been in the family since new. Pretty good condition overall, but with everything old. It will need some clean up and some reconditioning.


Powered by the first in a long standing family of Duramax Engines.

The 2004 Duramax was the last year the LB7 was offered. The LB7 was GM's first Duramax. And the first diesel engine with aluminium heads. The LB7 also sported common rail fuel injection. Which in turn made for a simple reliable fuel system..


Halfway into 2004, GMC brought out the next Duramax engine. And the LB7 was replaced after 2.5 years of service. The new Duramax, the biggest improvement was the fuel injector, and its placement. Which we will cover in a future fuel system blog post. Smog equipment was also added to all Duramax trucks going forward.


As of the last 2 years. These trucks have increased in value. Mainly because of the lack of smog equipment. The LB7 was offered in two versions. California/Fleet, and Federal. And as you can guess. California/fleet has the smog equipment only. Which is pretty simple EGR and Cat. Not many of these are left.

The Federal version from the factory. Doesn't have any smog equipment. And has a longer engine life span and slightly better reliability.

As long as you keep up on maintenance. Both versions are very good trucks.


Stay tuned for more!

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