BIG BLUE V3.0
Big Blue, the 1968 GMC C2500 is the O.G for us, the prototype and test mule for many of our products we have designed and developed. Over the years we have transformed this low-mile, highly optioned, factory big block truck into what you see today. After landing here in Australia in 2022, it underwent a restoration including full bare-metal respray in the factory medium blue hue, which was slightly tweaked by us, the 396 engine had a rebuild, throwing in an angry cam and big converter, some diff gears and a tru-trac and suspension and chassis modifications including drop spindles and a c-notch to get it as low as you see it here rolling on 22" wheels. During that time we found an owner for it, who loved it more than we did, if that was even possible!
It came back to us in 2023 for more goodies, we designed and developed our 90mm bed raise kit, bed braces and timber bed kit, right on this truck. This truck came to us with a steel bed and left with the Aussie hardwood you see here.
In that time it was here, the owner mentioned to us how bad the fuel economy was of the big engine, regularly travelling big distances for car shows and weekend trips. It made a bunch of torque and even more noise, but it was time to bring the 50+ year old driveline into the 21st century. Over the next few months we mapped out some engine and transmission scenarios for the owner, ultimately resulting in an injected and cammed LS3 engine and 6 speed electronically controlled 6L90E GM Transmission. We got to work, sourcing the LS3 from So-Hem Kustom & Supply, our friends at Peach Performance undertook all the machine-work and bolted the package together for us, we sourced a very low-km 6L90E box and had it checked over, all done prior to the truck coming back to us.
The LS3 received the Chevy Orange treatment, done in solid 2k, 2-piece vintage style Holley rocker covers with the Chevrolet script, single plain injection manifold with the 4150/throttle body adaptor and an LS Classic Air Cleaner to finish off the look. For the front drive assembly, a Heavy Metal Garage front drive kit was used, moving all components lower while still utilizing a serpentine belt.
Once the truck arrived to us, we disassembled the entire front of the truck, removing all front sheet metal, driveline, all firewall components and chassis components, ready to mockup the engine and start designing engine mounts.
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With the engine and transmission situated perfect and level, our sliding engine mounts gave us plenty of adjustment back and forward to allow for more clearance for front drive accessories and headers. At this point we measured up for a new tail shaft, we used Driveline Services for that job, who made us a brand new 2-piece unit.
At the same time our driveline was being mocked up, lots of work was being done inside the cab, including installing a full Vintage Air under-dash unit along with factory correct A/C dash vents. The vents needed to be cut into the dash frame, so a template was made from a factory A/C truck we had. The evaporator unit was placed behind the glove-box so it wasn't seen from inside the cab, custom mounts were made.
The dash was stripped from all wiring and components, prepped and masked up before it got a new coat of blue, with the vents, cluster surround and glovebox lid also getting coated.
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The firewall also received the same treatment, we fabricated some firewall panels to delete the factory heater holes, and also houses our new A/C bulkhead. The firewall was then smoothed over and some factory imperfections fixed then coated in that same blue metallic! The chassis was blasted and coated in satin black 2k.
The driveline went in for the last time, now the engine got dressed and the new standalone loom using the factory GM E38 ECU could be run and terminated. The 6L90E was shifted by a linkage from the factory column. The new custom alloy radiator went in, making new brackets for it, aswell as the coolant overflow, power steering reservoir and washer bottle. New inner fenders were sourced and painted in the factory blue. Once they were installed then all the wiring and plumbing to the rad support could be run.
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The new Wilwood master and booster installed, new stainless brake lines were made up. A/C lines ran and crimped, hidden through the chassis where we could.
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We had the factory 396 "Turbo Jet" 350hp sticker recreated for the LS3 with the updated hp figure.
The owner opted for Varex mufflers, which had an exhaust valve actuated by bluetooth, so it could be quietened down from the touch of a button. The system is a twin 2.5" stainless, x-pipe crossover, finished up dumped at the diff.
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We finally hit the dyno, Power Torque Engines put a killer tune in it, making a little over 400rwhp on a hub dyno.
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A few little final touches to the inside of the cab, we created this A/C panel for the Vintage Air, in the factory spot. The GM ECU was tucked under the dash, we created its own mount using our 3D scanner. All the electrical work was done in-house, we removed 95% of the factory wiring and created completely new looms using blade fuses and relays replacing the old glass fuses and fusible links.
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And the final result, we spent 5 months deep in this truck, especially in the engine bay and interior creating the owners ultimate dream truck. Basically every box ticked, 500hp injected cammed LS3, 6L90E 6 speed auto, with sports mode on the column, ice cold A/C, Wilwood brakes, bi-modal exhaust and the list goes on.. the difficult part was to make it look factory, while adding our own custom one-off style.. All in-house!
