"New" Duramax 6600/Allison Suburban
From the archive here at TheDieselPage.com... What follows is/was an article that appeared here in The Diesel Page in the early 2000's about an enterprising GM enthusiast who put together a "new" Duramax 6600 powered Suburban using brand new components acquired from a variety of salvage sources. This article is now being made available to the public as a way to demonstrate what was then and remains possible today - to get what you want in a vehicle. I've been asked many times during these past 20+ years "if" a Duramax/Allison could be swapped into an NBS (New Body Style 1999-2007) full size pickup truck or SUV. A recent visitor to our YouTube channel asked this question as well. This archive article will hopefully answer his or anyone's question about the viability/possibility of such a swap. I ponder such a swap using a brand new L5P Duramax and brand new Suburban body... Jim Bigley
Duramax/Allison Suburban HD
The best just got better!
Text by Jim Bigley
Photos by Gene Wonders
Chevrolet's flagship SUV just got a significant boost in power and capability. Effortless towing and the potential for 20+ miles per gallon make this arguably the best Suburban ever... Unfortunately, it's not available from General Motors.
Since offering the Duramax 6600 as an engine option for their HD pickup truck line, GM regrettably no longer produced any diesel powered Suburbans. Not content with this situation, Ohio resident Bill Armstrong decided he had waited long enough. Ingenuity and motivation have produced the first privately owned Suburban equipped with the 300 horsepower Duramax 6600 and Allison 1000 series 5-speed automatic. Here's Bill's story - about how his new Suburban came to be.
Component list:
New 1500HD Suburban body.
New 2500 Avalanche frame from firewall rearward.
New 2500HD front suspension & frame from firewall forward.
New 2500HD rear axle and suspension components.
New 2500HD front clip (fenders, hood, grille & bumper, etc.) and radiator core support.
New & complete Duramax 6600, Allison & transfer case with all necessary components.
2" body lift to match HD front clip and to clear the Allison.
It should be noted that this Chevrolet Suburban was assembled from all new components. It is essentially a brand new vehicle - and is unique to say the least.
All of these components were purchased from commercial auto parts vendors who deal with General Motors on an ongoing basis, and can offer new "salvage" components for many GM products. The Suburban body used by Bill, for example, was sold as salvage because it had sustained some mild damage while being loaded onto a transport trailer at GM's assembly plant. The remainder of the vehicle components used in Bill's project became available for similar reasons.
Rules apply to all major component part purchases. Bodies can't be sold with a complete chassis or drivetrain all having matching serial numbers. This shields both GM and salvage dealers from on-road vehicle liability responsibility, damage claims or EPA regulations. For example, customers can buy an individual body, frame, chassis component or engine/transmission to repair an existing vehicle, or they can buy a complete "set" of non-serialized parts for a special project (like this Suburban). The "assembler" assumes the responsibility of vehicle liability or regulation compliance.
Aside from having a distinct preference for GM vehicles, Bill is also a respected Midwest truck enthusiast who has built competition sled pull trucks for many years. Those who have seen the quality of Bill's metal fabrication say it is first-rate. This, in part, makes Bill eminently qualified to assemble his own Suburban.
The 2500HD that donated the engine was equipped with a snowplow option. Part of the package included dual alternators, which might not be a bad idea for a Suburban with the rear heat/air option.
Bill has indicated that a 2500 series Suburban body might have simplified the assembly process. It appears the 1500 and 2500 series body mounts and accelerator pedal mounts are located a little differently. Using all 2500 series components would have eased assembly somewhat. A new four-wheel drive selector switch panel was also necessary to properly control the NPG-263 electronic transfer case.
The dual gasoline fuel tanks were reconfigured for the diesel engine as well. The original "in-tank" FI fuel pump was removed, and a conventional diesel fuel pickup tube was installed. As this was being written, the fuel transfer between the dual tanks was one of the last remaining puzzles to solve.
Thanks to GM's product line cross-compatibility, the only truly custom items necessary to complete this project were the body filler piece from the rear bumper to the body, the rear driveshaft and some work on the AC lines for the rear air conditioning system.
The two most frequently asked questions are: 1- What's it like to drive and 2- how much did it cost? Only a few weeks have passed since completing the Suburban. Ohio requires (as do other states) an "owner assembled" vehicle to pass a rigorous vehicle safety inspection and component purchase verification before being issued a title and registration. This process can take a couple of weeks to complete, while the Highway Patrol goes over the vehicle with a fine toothed comb. However, in the short time Bill has had to drive his new Duramax Suburban, he reports an exhilarating ride that draws considerable attention.
A surprise visit to a local Chevy dealership literally shut down their operation while sales, management and customers poured over Bill's awesome new Chevrolet Duramax/Allison Suburban HD.
As far as the cost is concerned, we suspect that if a factory Duramax/Allison Suburban were to ever become available, a well-equipped version would list for something in the $50K USD range. Not counting a boatload of labor, Bill's Suburban came in at less than half that. Great effort, great result and a source of envy for many GM diesel enthusiasts who long for a Duramax powered Suburban. TDP
Note: The appearance of this article back in the early 2000s inspired several individuals, from Florida to California, to launch a new business focused on producing Duramax Suburbans. There was a time when professionally built and looking 2500 series Suburbans were selling for at least $20k above the Kelly Blue Book vehicle pricing guide for the same vehicle equipped with a gas engine. The stories about the chaos (good kind) that occurred when a Duramax Suburban owner visited a local GM dealership, or having other motorist follow you into parking lots or rest areas to ask whether this was "really" a Duramax powered Suburban are quite entertaining.
Did this forum thread or YouTube video help you with your conversion/swap? Would you like to share this information with others or help us get the word out about Duramax swaps? It's easy! Simply link to us in your own YouTube video, or post the link(s) shown here in a forum post, email message or social media site. Thank you!
www.thedieselpageforums.com/tdpforum/showthread.php?47264
https://youtu.be/--9bY1T3XoQ
Jim
Reply With Quote
