Car building trends have traditionally ebbed and flowed between outrageously wild outlaw machinery and clean, simple streeters. Gearheads would build wilder and wilder cars until Johnny Law would crack down on them or owners would get sick of living with flat-out race cars on the road, and then the pendulum would swing back to a focus on detail rather than race-inspired engineering and trophy-winning body mods and paintjobs. Lately, however, we’ve seen a new trend on the rise: street elite.

First published in the December 2025 issue of Street Machine

Take this epic ’57 Buick Special coupe, built by Warhorse Motorsports in Rutherford, NSW and owned by Novocastrian Jason Roberts. The glowing Mazda Soul Red paint, pin-sharp bodywork, slammed stance, and bespoke interior all scream ‘show car’, while the 600rwhp powerplant gives it the vibe of a true street machine. But the big land yacht hides its engineering smarts with dual-zone air-conditioning, an electronic six-speed auto, wireless phone charging, power windows, air suspension, and more.

“The car was never built to be shown; it was built with the intention to drive and for it to be comfortable while doing so,” says Warhorse’s Brad Lowe. “Anywhere we could use a standard part from a regular parts store, we did, just for maintenance purposes. There are obviously a lot of custom parts on the car, too, but we wanted to ensure Jason could service the car at home without having to come back to the shop for little trivial parts.”

Even the car’s name, Capo, calls back to the streets. “Capo is short for ‘Caporegime’,” Brad says. “Jason came up with the name; Capos are high-ranking positions in the mafia, sometimes referred to as a ‘street boss’.”

While the amount of work undertaken by Brad and the Warhorse team is huge, Capo has been created in only a few short years. “It was dropped off to WM just over three years ago as a stripped, stock, left-hand-drive ’57 Buick,” Brad says. “It only had a little bit of rust around the boot and the tops of the rear guards, but there was some bog we had to dig out of it, and it was missing its X-frame chassis.”

Work began with a Scott’s Hotrods independent front end featuring right-hand-drive rack-and-pinion steering, while the frame rails were boxed for strength and a whole new rear clip was designed and fabricated by Warhorse. This included moving to a custom four-link set-up with a shortened nine-inch hung from it, built by the Warhorse crew.

“All the engine bay sheet metal, the air intake, firewall, custom fuel tank, transmission tunnel, rear floors, and wheel tubs are custom-made by Warhorse,” says Brad. “The chassis was chopped off in the front and rear, and the centre sections were boxed in. We also decided to build the car as a four-seater, with the idea to have the seats feel like passengers were sitting in armchairs. Capo was also completely wired and plumbed by WM.”

Under the bonnet, the stock Buick ‘nailhead’ mill has been turfed, which would probably upset anyone who hasn’t tried sourcing vintage Buick parts from Aussie stores. In its place, a Harrop-supercharged LS3 was given the nod, which Warhorse then rebuilt. “We started with a second-hand LS3, stripped it right down and rebuilt it so it would be reliable,” Brad says. “It didn’t need too much work, as the Harrop 2300 blower won’t kill a stock rotating assembly.”

The factory hardware, including the 10.7:1 compression ratio, deep-breathing #823 cylinder heads, and 1.7-ratio high-lift rocker arms, lay excellent groundwork for making power. Warhorse added a Crow 238°/250°/114° hydraulic-roller cam and LS7 lifters to this combo, along with the Harrop 2.3-litre belt-fed intake, and a Holley Terminator ECU.

Drinking straight 98-octane premium unleaded and running just 12psi of boost, the basic combo stomped out a potent 600hp at the hubs, which is easily going to be enough to turn the 335-wide Continental tyres out back into puffy white clouds.

Capo may have been built for a life on the Newcastle streets, but Warhorse did stitch themselves up when they decided to debut the car at the 2025 Sydney Hot Rod & Custom Auto Expo, which meant a massive thrash to get the big Buick ready on time.

“That decision definitely threw a spanner in the works, as the car still needed interior, wiring, paint and panel, fabrication, and building the engine, and we only had 100 days to do it all,” Brad laughs. “We had up to 12 guys on the car at a time for the four weeks leading up to the show, and in the last week, each of the Warhorse crew did one or two 24-hour shifts.“

It certainly went right down to the wire, with Capo not finished until 4am on the bump-in day of the Expo. Jason hadn’t seen the car pieced together or the design of the interior until it rolled out of the trailer at the show, and his wife hadn’t laid eyes on it at all until the covers were taken off it at the unveiling.

Now that the Buick’s been shown off as a testament to the Warhorse team’s skills, Capo is currently undergoing engineering approval so it’s sweet to roll on NSW roads.

“Jason has never pushed us to get the car done, but he does want to drive it for summer, so we’re just buttoning up the last few things now,” says Brad. “Every single thing on the car is made in-house, bar the IFS, so I’m proud of it.”

JASON ROBERTS
1957 BUICK SPECIAL COUPE

THANKS
Warhorse Motorsports crew; Mob Engines for the block machining; Powder Coating Industries; Gardiner Automotive for tyres and wheel alignment; Muscle Car Imports for parts supply; Glass 4 Classics; Define Detailing; Full Tilt Towing; Rod’s Total Tint.