One of the all-time greatest Aussie automotive designs, the HK Monaro remains a fabled chariot for street machiners and classic car enthusiasts alike. While they’ve been built into crazy race cars or restored to better-than-new condition, the appeal of a clean and tidy HK GTS street car is too hard to ignore for many Aussies – including Bruno Cavallo, the owner of the killer ’K you see here.

First published in the June 2024 issue of Street Machine

“They’re an iconic Aussie muscle car, and I chose an HK because I love the shape of the car,” Bruno says. After decades of race cars, including six-second, stick-shift Pro Stockers (see more below), Bruno wanted a ride he could enjoy on the street with his family. But while a factory HK’s looks might be timeless, the driving manners of Holden’s first coupe certainly aren’t. “I wanted it to look old, but I am not a fan of how the old stuff drives,” he says.

It didn’t take Bruno long to find a suitable HK shell that had already been stripped and the bodywork started. “After I bought the HK, Shawn from Exotic Kustoms soda-blasted it so he could see what he was working with,” he says. “I saw it after it was blasted and the decision was made to start again; it’s a forever car, so it had to be done right.”

The Exotic Kustoms crew had the swoopy two-door back in svelte form in no time, and then laid down the bright House of Kolor white. While many think HK Monaros only come in Warwick Yellow or Silver Mink, Bruno wanted to stand out with this special project.

“It was a blue V8 car originally, but everybody wants a Silver Mink, so I wanted to be different,” he laughs. “I also think the Goya Red stripe and detailing helps. There are little Goya Red touches outside, like on the wheelarch trims and centre caps, and we went through quite a few colour samples before we found the shade that worked. It all needed to come together with the white paint to work as a package.”

With Bruno wanting to vastly improve upon the HK’s original soggy on-road behaviour, a new Magnum GX front end from United Speed Shop was fitted, with the old steering box and drag link set-up binned in favour of a modern rack-and-pinion system.

After decades of race cars, including six-second, stick-shift Pro Stockers, Bruno wanted a ride he could enjoy on the street

The drivetrain was another important part of the project that had to function as a cohesive unit, and Bruno blended old-school with modern to find his perfect match. General Motors’ 6.2-litre LSA crate motor offers a killer 580hp kick with all the reliability of a nice, fresh modern car, so it was a no-brainer for Bruno’s HK project. He left the stock engine cover off, instead detailing the mill with custom exhaust and intercooler systems, a larger throttlebody, finned coil pack covers, black fuel and coolant fittings, and a CVR billet front accessory drive.

Some might prefer a grumpy old-school donk to a smooth-running LSA, but Bruno had practicality in mind. “I wanted power to be there on tap when you want it, and I wanted to get away from fumy old engines,” he says. “My Chevy pick-up has a strong small-block in it, and my wife hates the fuel smell from it; you just don’t get that in the HK.”

The LSA sits in a super-sanitary engine bay that belies the amount of fab work Mat from Elite Street Classics had to do to get it looking that way. “Mat did an amazing job, as he made the exhaust, custom intercooler tank, airbox and all the engine bay fabrication,” says Bruno.

Behind the late-model alloy small-block is a traditional street machine drivetrain of a Powerglide auto and a nine-inch diff. They’re not stock-spec though, with an SDE 3000rpm converter working the Protrans-built two-speed, and Supa Trik Diffs kitting the third member out with a Strange Engineering centre, Truetrac and 35-spline axles.

One of the most difficult aspects of the build was chasing down the necessary parts so that Mat at Elite Street Classics could handle the final assembly. “The car was just a bare shell when I got it, and Phil Bartolo helped me by finding parts to finish it all off,” Bruno says.

Despite having to overcome body issues and re-engineer the car to steer sweetly, Bruno had his slick HK completed inside a three-year window, which is epic considering the quality of the finished car.

“We brought it home on 23 December 2022,” Bruno says. “I said it was my Christmas present to myself, and I even got to unveil it to the family on Christmas day. After that, we got it engineered and registered, and now I drive it as much as I can. I’ll probably drive it up to Bright this year.”

For Bruno, going slower has never felt so good!

LIFE OF SPEED

Many readers would be keen to hear what Bruno’s HK can do on the quarter, but his past with hand-built Pro-class race cars means he needs way more spice to get him fired up about racing these days.

“I’ve got racing out of my system now, and for me, this car is still slow,” he laughs. “The Pro Stock cars ran high sixes at over 195mph; obviously a street car is a lot different to a purpose-built race car, but I’m still not interested.”

Ironically, Bruno’s path to Pro Stock began with streeters. “My racing started with a hatchback Torana – just as a street car at Calder on Sundays – and then it progressed to buying a Windsor-powered RX-7 Super Sedan. I blew up the motor, so we ended up tubbing it and putting a big-block in it. We then built a tube-frame, big-block VH Commodore and ran that for a year before we moved to Group 2 Super Stock with a small-block and manual. That lasted for a few years.”

Bruno then moved to an American-built Pontiac Firebird, again in Group 2 classes, with small-block/stick-shift combos. “I reset multiple national records and was national champion a few times,” he says.

“Following this, we then stepped up to Pro Stock around a decade ago,” he continues. “These were 400ci, naturally aspirated small-blocks that we pushed from 900hp up to 1100hp by the time I finished racing. They were great to drive when everything was working as it should and the car set up was right.”

BRUNO CAVALLO
1968 HOLDEN HK MONARO

THANKS
Mat at Elite Street Classics; Phil at Progen Performance; Jason at Race Radiators; Andrew at Supa Trik Diffs; Phil Bartolo the HK-T-G specialist; Chris at Race Wires; last but not least, my family for their support.