Words: Isaac Western Photos: Aaron Mai
Featured in Issue No. 227 — Grab Yours Here
There’s a secret — a common thread that runs through the story of most things fast and expensive. When you really need to let loose on something, to create a once-in-a-lifetime machine, there’s often only one way to start without making things difficult for yourself. Those who are skilled in this technique can go on to create absolute marvels of engineering, and for those who aren’t, it’s a risky game. For Hayden Brown, it seems as though he’s got the hang of this secret because that’s exactly how this nutty Cummins-powered GMC C10 build started out. By making a little deal with the Wife.
Hayden and Kristina had been working hard on their farm for an age already, so the deal was this: if they can get off the farm, to somewhere with less bloody cows, he’d have free rein to use the spare cash from selling animals to build a hot rod truck. Having seen Hayden pedal his fair share of fun ‘money pits’ already, such as RX-2s, Silvias, and even a Ford Galaxie, we’re sure she had a rough idea of the costs involved in such a deal. But looking at how this build turned out, you have to hand it to her for supporting this project until the end and not looking at the receipts too closely — especially when at one point, it seemed that they’d need to cut their losses. More on that later.
Before that, though, with arguably the trickiest part of the project out of the way, Hayden had full blessing to dive into his dream hot rod build. For many people, this could even be an overwhelming moment, but Hayden knew his main requirements — one being diesel, and the other being truck.
He’d actually started training as a diesel mechanic shortly after wrapping the farm up, and he already had ideas bouncing around his head thanks to Cummins engine enthusiasts on YouTube — Power Driven Diesel, and Cutterup Rob.
He called Kendal and Dylan Smith at Kruzin Kustoms in Palmerston North and chatted at length about trucks, sharing ideas back and forth. They were excited to do something a bit different. Hayden had initially thought about building a square body C10, but after some extended consulting with the Kruzin Kustoms team (and also his wife, Kristina), Hayden decided on a 1964–1966 GMC or Chev. They just had a charming character to them, and looked great — especially when dropped on the floor.
After giving the go-ahead to Kruzin Kustoms’ sourcing wizards, they soon conjured up a white 1965 GMC C10 from San Francisco. It was originally a long-bed but had been converted to a short-bed in the US, with a Chev deck put on it, plus a ’62 Chev front grille. Thankfully, it had a mint, complete body. The chassis wasn’t anywhere near as tidy, though, and it had to have a lot of work done. With a truck like this, luckily, it’s easier to fix up a chassis frame than to try and replicate the intricate body panels.
With the body on its way, Hayden then turned his attention to the engine. In his books, nothing beat the reliability and tunability of the Cummins 12-valve. The sound was another big draw, as arguably the best-sounding diesel around.
While his heart was set on the 5.9-litre Cummins straight-six, Kruzin Kustoms hadn’t done a full diesel build themselves before. Everybody agreed that it was probably best if they all stuck to what they were good at, so Hayden took it upon himself to source the engine. He ended up finding an Australian outfit, Cummins Performance, with connections to the main Cummins factory in China. They build crate engines to ship worldwide that people drop into Nissan Patrols and the like. He promptly ordered his brand new 6BT 12-valve Cummins; the perfect blank slate to work with when the goal is to roll coal.
When it came to decide which transmission to mate this torque monster to, having the free rein of being a dream build, Hayden knew it had to be a manual. This ended up being an excruciating rollercoaster of emotions, however, because after paying up front for a five-speed NV4500 box from CPP Diesel in the states, he heard nothing back. Months, and months and months passed — other parts of the build progressed, but still he couldn’t get a response back from this company. What were these guys doing? When you drop several thousand on a large purchase like that, you don’t expect to deal with a ghost. Eventually, after a frustrating five months of no word, he decided to cut his losses, and ordered another transmission, this time from Canada.
Lo and behold, as these things tend to go, after nine months of battling to hear back, both transmissions turn up within the same week. Would you believe it? Thankfully, now that Hayden had done the hard yards to get it here, it was ready to be snapped up by a hungry NZ manual market. There’s now a happy bugger somewhere down South with a freshly manual Dodge Ram, who helped Hayden not only recoup his costs, but surely the health of his marriage as well. It was apparently a very long nine months …
Now, after painstakingly gathering all of these components from around the globe, both Hayden and Kruzin Kustoms were finally free to crack on with the build. Performance parts and fuelling upgrades were sourced from Power Driven Diesel in the US. A PDD Aggressor 62 Turbo and a front mount intercooler was added to give the Cummins more pep. A sizeable AirDog Lift Pump, 5×0.013-inch PDD injectors, and PDD 025 Delivery Valves were added, with an AFC Live fuel tuner from PDD to help manage things nicely.
To help it breathe, they fitted a Banks Twin-Ram intake, and a PDD air filter. On the exhaust side, Matt from Kruzin Kustoms created a custom piece, going into a mix of oval and round four-inch pipe to side-exit just behind the cab — with some beautiful pie-cut work in between.
To fit this freshly garnished Cummins in, the firewall and transmission tunnel were stretched to leave room for the 5.9-litre cast iron mill. Because of the weight of the engine, a brand-new front suspension and cross-member layout needed to be looked at. Kruzin Kustoms and Heidts Automotive worked together to beef up the existing Heidts-offered C10 front end, with the newly upgraded design now available in the Heidts catalogue.
When it came to suspension, Hayden knew he wanted to lay some frame, but also needed to actually enjoy driving it. This meant modifying the front fenders and hood hinges to make way for the new wheels, whenever the Ridetech ShockWave air suspension was aired out. Behind the cab, the entire four-link rear clip was created by Porter Built Fabrication, and looks seriously impressive when Hayden’s home-built, actuated macrocarpa deck floor is lifted.
Between the NV4500 five-speed and the rear, a custom two-piece driveshaft was crafted by Kruzin Kustoms, sending power to a Strange differential with a limited-slip centre. A full Wilwood brake system was fitted to bring this beast to a halt — 13-inch discs up front, 11-inch at the rear, with a Wilwood master cylinder. To get the power to the ground, 285/35R20 Toyo tyres were fitted to the rear, and sizeable 245/40R18s sit up front. Hayden had always loved the look of smooth wheels on a sacked truck, so Detroit Steel D-Town Smoothies were an easy choice.
After some rust removal from the roof, windscreen surround, A-pillars, and sills, plus some work to fix up the sad original chassis frame, it was then time to move to paint. A black chassis was definitely off the table for this build, and Hayden had never seen a red frame before. So after Kruzin Kustoms’ help on paint research he settled on Desert Red Wrinkle from Prismatic Powders, and sent it off to Central Powder Coaters in Palmy. For a while, his friends said that it was “a bit out there”, but once the accent colours started coming together, people started to see Hayden’s full vision.
The engine accents, wheels, fuel cell, and driveshaft were painted in Ceracote Bronze, which gives a clean, modern look in the engine bay while also looking somewhat period-correct on the wheels. It all seems to mix well with the mostly original off-white exterior paint, and sets the tone for the beautifully re-done brown interior.
Being a single cab, there wasn’t too much needed on the inside, but a remarkably fresh leather bench seat was sourced by Dylan at Kruzin Kustoms. Hayden kept the natural look going with a Grant Classic Wood steering wheel, and included a Dakota Digital dash to talk to the new engine, along with gauges for boost and EGT.
All wrapped up, Hayden’s finished truck is definitely something that will make you double-take at a car show. It’s tasteful and classic at a glance, still providing a strong presence — especially when aired out. And then, as each compartment on the truck opens up, you see that he’s done something very different to the usual, and all in beautifully engineered, well thought-out, rock-solid fashion. With a bulletproof Cummins at the heart, and thick ‘60s steel, both Hayden and his wife will be enjoying his dream creation for decades to come yet. As long as he keeps the receipts hidden …
Vehicle: 1965 GMC C10
Engine: Cummins 6BT 12-valve crate engine, stock internals, 120lb valve springs, Banks Twin-Ram intake, front mount intercooler, Power Driven Diesel air filter, Power Driven Diesel Aggressor 62 turbo, AirDog lift pump, Power Driven Diesel 5×0.013 injectors, 025 Delivery Valves, custom four-inch exhaust, upgraded C10 radiator, AFC Live fuel tuner
Driveline: New Venture Gear 4500, standard 13-inch flywheel, single plate clutch, Strange differential, limited-slip centre, custom two-piece driveshaft
Suspension: Heidts front crossmember and suspension, Ridetech ShockWave air ride, Porter Built rear four-link
Brakes: Wilwood master cylinder, Hydroboost booster, Wilwood 13-inch front discs, 11-inch rear discs, Wilwood calipers
Wheels/Tyres: 18-inch and 20-inch Detroit Steel Wheel Co. D-Town Smoothies, 245/40R18 and 285/35R20 Toyo Proxes tyres
Exterior: Modified front guards, actuated deck tilt, deck floor lifted, macrocarpa deck, original paint buffed
Interior: Leather bench seat, Grant Classic Wood steering wheel, Dakota Digital dash, boost and EGT gauge
Chassis: Boxed stock chassis, Desert Wrinkle Red powdercoat
Performance: 350hp / 700lb-ft
Driver: Hayden Brown
Age: 39
Occupation: Diesel Mechanic
Previously owned cars: ’96 Nissan Silvia, ’74 Mazda RX-2, ’67 Ford Galaxie
Dream car: This is it, I love it
Why the Cummins? The Cummins 12-valve sound is just the best-sounding diesel engine. It’s reliable and completely mechanical, so I can do any future mods without computers.
Why the GMC? I always wanted to build a truck, and I love diesel power. Just had to put the two together.
Build time: 3 years
Length of ownership: 3 years
Hayden thanks: My wife Kristina for supporting the build, and being OK with not knowing how much I spent on it. Biggest thank-you to Kruzin Kustoms for the awesome engineers that work there, and the filling of the gaps in every direction of the build; Matt and Dylan, as well as everyone else that worked on it; Isaac from Manawatu Auto Electrical for the awesome wiring job; Auto Interiors Ltd for the carpet install.