Mark Bartyn’s 434-cube Holden HK Kingswood

Over seven years, young gun Mark Bartyn transfomed his HK Kingswood from relic to riot

Photographers: Phil Cooper

When you spend your formative years helping your dad work on his beloved HR in a shed decorated with Holden imagery, you can be fairly sure that, when the time comes, the logo of the lion and the stone will adorn your chosen ride. That was certainly the case for young Mark Bartyn, whose immaculate HK Kingswood you see here. “I can appreciate a good Ford, but I do prefer the Holdens,” he says.

First published in the March 2023 issue of Street Machine

Mark’s car journey started young, apparently pretty much as soon as he could walk! “I was always helping Dad or getting in his way,” the Sydneysider recalls. “It’s something that was born into me, with my pops being into cars as well.”

Once Mark finished school and gained himself an apprenticeship as a plant mechanic, the search for an HK was on. “I always liked the shape ever since I was young, and I wanted something different from the Toranas everyone had when I was growing up,” he explains. “There were plenty for sale but a lot were rust buckets.”

It took about eight months, but a suitable HK was eventually found on eBay. Based in Victoria, the car had been retired in 1990 and put out to pasture. Mark remembers his first impressions: “The reason we bought it was that you could see all the rust. It was all original paint, and nobody had bogged over any problems. You could see what you were getting yourself into. It was a pretty honest car.” A fistful of dollars changed hands and suddenly Mark was the proud owner of a 1968 HK Kingswood as his first car!

If you’ve had even the faintest whiff of custom car building, you would have been sharply brought to your senses by the realisation that it usually requires very deep pockets. How then can a Summernats Top 20 car be crafted on an apprentice’s wage? Mark says it came down to his dad’s knowledge, his own determination, plenty of time and a full serving of blood, sweat and beers. “Luckily for me, my old man and I did most of the work on it,” he says. “Really, we did everything except setting the diff up, the trim and building the engine and ’box.”

Once in the Bartyn shed, the HK was completely stripped, and a mobile sand-blasting company then tickled the bones back to bare metal. The exceptions were the outer skins of the panels, which were taken back by hand to eliminate the chance of heat-induced warp from blasting. Then all the rust was cut out.

Plenty of trial-and-error guided Mark through the learning process of cutting out the firewall and the boot floor. “Cut your way in and weld your way back out” was the format, according to him. Once that was done, Xtreme Fabworx fabricated new firewall and boot panels, and the rebuild then began.

Mark had never really welded before, but if he wanted to keep costs down, he knew he’d have to learn in a hurry. “The hardest part was the custom under-dash brake booster and master cylinder,” he says. “That was a punishment to fit – welding and grinding on my back under the dash, sparks falling in my eyes.

“We fitted the car up a fair few times to make all the panels straight. We put all new door skins on it, so we had to make sure the doors all lined up and all the gaps were good. Then we stripped it all back to nothing again ready for paint.”

Happily, Mark’s dad, Brad, is a painter by trade, so the panels were sprayed at home, while they coated the shell in a booth that their mate Adam owned. Reassembly took place again and the paint was rubbed back ready for flowcoating.

After one more time in the booth with Dad – this time at Grange Smash, owned by another family friend, Kev – the HK emerged resplendent in its new Cromax Firenze Red clothes. “Dad was out there all the time with me, helping me, giving me tips on what he thought I should do,” Mark says. “He was a big help along the way – saved me lots of money helping and painting it for me.”

Bolting in the new hardware was time-consuming but fairly straightforward. A tailored Rod-Tech independent suspension system came packaged with adjustable coil-overs and VR Commodore disc brakes. Finishing off the front end is a Rod-Tech-supplied power-steering rack, with a Holden Astra electric pump seated in the boot.

Power is distributed at the rear through a 1500hp-rated sheet-metal nine-inch with a Strange centre and 3.89 gears. Thirty-five-spline axles with 5/8-inch studs deal with the extra shunt. A McDonald Brothers triangular four-link was welded in to keep everything in place, while Strange adjustable coil-overs take care of the ride and stance. VR Commodore discs and calipers were again given the nod out back.

To get the power down, 15×8.5 Street Pro Convo Pros with a 3.5-inch backspace were dressed in 275/60 rubber and loaded into the mini-tubs. The same rims in 15×4 guise with 165/70 boots are responsible for direction.

The build was an epic task, and a bold move for a first-timer leaping into the big league. But fortune favours the brave, so Mark rolled up his sleeves and marched into the shed most days. “I used to try and be out there every afternoon after work to smash it out, and some nights I’d stay out there ’til midnight,” he recounts.

As 2020 dawned, the build had already been underway for five years, and with Mark itching to drive the car, it was time to get the project finally rolling under its own steam. Unfortunately, the coffers had been bled dry, so he couldn’t afford his dream donk yet. In the meantime, he was able to get his hands on a 383 to fill the void. “That was just for until I could save up a bit more money and buy a bigger engine,” Mark explains.

That motor spun a bearing after six months, so to keep the wheels turning, a 350 Chev block that was sitting idle in a mate’s shed was dusted off and brought home. Enough change was then scraped together to get the required internals.

With 757hp on tap, it only takes a twitch of the toes to chang the weather to cloudy

“I honed it, got all-new pistons, rings, gaskets and bearings, and built the motor myself,” Mark says. The top end of the 383 was transplanted on top of the 350 block, and the result saw out the next 12 months until the last chapter – the big engine – could finally be written.

Scott from Woody’s Performance has been building donks for the family for 20 years, so they knew he was a solid choice for the big-ticket item. A knock on his door, a brief chat and nine months later the crowning glory emerged from the workshop in the shape of a 434 small-block Chev with 757hp worth of flywheel sting. This was mated with a two-speed Powerglide with a transbrake, which, being good for 1000hp, is certainly up to the task.

Cooling’s always a serious consideration when you’ve upgraded the amount of grunt under the lid. Some consult a specialist, while others bury themselves in the literature to decipher the facts and figures and come up with a number.

Mark knew that the AU Falcon radiator and fan combo was a well-respected set-up, so he bought a $200 rig off eBay. Good move: no matter what Mark throws at it, from standing in traffic on a hot day to doing burnouts, the temperature gauge barely flinches. “I just leave the fans on all the time; then I don’t forget about turning them on,” he laughs.

The number plates warrant a mention. They belonged to a family friend, Rob, who was also building an HK and always joked that he’d be finished before Mark. Unfortunately, Rob passed away, so Mark bought the plates. “The number plates mean a fair bit to me,” Mark says. “I put his number plates on my car to keep his dream alive.”

The HK has mild enough manners down low for an easy ride to the shops, but with 757hp aching to break free, it only takes a twitch of the toes to change the weather to cloudy. “With that front suspension and power steering, it drives like a new car,” Mark enthuses.

As for future plans, Mark says that some roll racing and trimming the boot are on the radar, but at the same time, he reckons the car’s fine just as it is. “It’s sort of where I like it now,” he says. “I always wanted that bigger engine, and I’ve finally got that. I just want to drive it and enjoy it now.” Amen to that.


Paint:Cromax Firenze Red
Brand:434ci small-block Chev
Block:Dart Little M
Heads:Brodix 18-degree
Carby:1050 APD 1050cfm
Cam:Custom-grind Jones solid-roller
Pistons:Custom Diamond
Fuel:Aeroflow cell, MangaFuel pump
Exhaust:Pacemaker headers, custom 3in stainless system
Cooling:AU Falcon radiator
Converter:SDE 5500rpm
Diff:9in, Strange centre, Truetrac, 3.89:1 gears
Front:Rod-Tech independent with adjustable coil-overs
Rear:Four-link with adjustable coil-overs
Brakes:VR Commodore
Master cylinder:RRS custom under-dash
Rims:Street Pro Convo Pro; 15×4 (f), 15×8.5 (r)
Rubber:Nankang; 165/70R15 (f), 275/60R15 (r)

Scott at Woody’s Performance; Cain at Xtreme Fabworx; Steve at All Trim; Al’s Race Glides, everyone who helped me along the way; biggest thanks to Dad – without him the car wouldn’t be where it is today; Mum for all the times she stopped Dad and I killing each other when we had different ideas of how things should be done!