Supercharged 1969 HK Kingswood

Coco Sheahan's eye-catching Turismo Blue HK Kingswood cracks nine-second quarters. How good are blowers?

Photographers: Chris Thorogood

THE transformation of Coco Sheahan’s HK Holden from a basic, white, 350-powered Kingswood into this shimmering, Turismo Blue, 6/71-blown, LS-powered weapon happened bit by bit.

First published in the December 2021 issue of Street Machine

Coco originally got the car as a replacement for a beige, vinyl-topped HK he’d been driving around Brisbane. He’d planned to swap the beige HK’s 202 for a 383 small-block he’d bought, but that changed when this white HK came up for sale that was already mod-plated for a small-block and Powerglide.

“It was pretty much ready to go,” says Coco. “So I thought I’d pull the 350 out and put the 383 in it, and I’d flick the beige HK.”

Coco drove the newly acquired HK with its 350 Chev for a while before the 383 went in, which is when he was first introduced to the legends at Spot On Performance.

“I ran into a bit of trouble; the pipes wouldn’t fit because of the angled heads on it,” Coco says. “So the bloke I bought the motor off, Mitchell Bean, told me to go to Spot On and they’d modify the pipes for me, and it sort of started from there.”

Coco had been tinkering with the ignition and doing small jobs here and there, but the boys at Spot On were keen to see the HK fully operational.

“I dropped it off in the morning and at lunchtime they rang me and said, ‘Do you mind if we just finish off the rest of the car?’ They said they’d have it ready that afternoon and I thought, ‘Geez, that would have taken me months to do.’ But they all just chipped in and, sure enough, that afternoon I drove it home!”

That was the start of a beautiful friendship, since Coco had not long moved to Brisbane from Bendigo.

“I didn’t have many mates up in Brisbane, so as soon as I met Danny and Andy from Spot On, they took me in as family pretty much,” Coco says. “Before you knew it, the small-block was in and they’d finished the car.”

‘Finished’ is always a loose term when it comes to cars, and it’s certainly an exaggeration to say that Coco’s HK was finished at that point. Next up, it had a tank of C16 and 150-shot of nitrous fitted, and made around 460hp when Justin from Horsepower Solutions strapped it to the dyno.

“It was a pretty stout little combo,” Coco says. “It went 10.80@119mph, and it would’ve had over 100 bottles of nitrous through it! We’d fill one up on a Friday night, load it up with the boys, go out to the track and end up in the city. It was a really great car.”

Then, after work one day, the HK was given another shot in the arm.

“I was at the shop and Andy said, ‘We should put a blower on it,’” Coco says. A mad rush ensued. “It started out as just a bit of a conversation and by the end of business hours we’d gone around and picked up carbies from Eagle and picked up the blower from Performance Wholesale.” The hole in the bonnet was cut, the job done. “It was probably about 12:30 that night that I drove it home with the new blower!”

A trip to Powercruise to see what the BDS 6/71 blower, running 18psi, could do started well. The HK was tearing through tyres and Coco was having a ball, until the final run, when the Kingswood lost power. “I pulled into the pits and I’d snapped the crank clean off at the front,” he says.

The small-block had to come out, which gave Coco the opportunity to clean up the engine bay. “Old mate at the panel shop goes, ‘Well, this is your time; if you want to change the colour, let’s do it!’ All my old cars have been blue, so I thought bugger it, and we painted it.”

You really have to see this car in person to get the full effect of the impressive paint and panel work. The Turismo Mica, a 2004 Monaro colour, sparkles in the sun.

To complement the punchy new paint, the factory red interior went and a supple tan leather was applied, with the standard steering wheel and column, glovebox lid and, of course, door tops linking the interior to the outside. The classic HK style is largely intact, apart from a B&M shifter and the Holley screen.

The 383 was given the heave-ho when an LS2 came up from a mate’s written-off VE SS Commodore at a price that couldn’t be ignored. The guys at Spot On sorted it out and built a fresh Powerglide for it.

“We were a bit unsure whether to go blown again,” Coco explains. “Back then, they didn’t sell off-the-shelf blower manifolds – everyone was making up their own. But then I said, ‘I don’t care how high it is!’”

That meant the Holley high-rise manifold went on top of the LS with a laser-cut top, to which the same BDS blower from the 383 was bolted. “We put it on and thought, ‘Holy shit, it’s high!’ But then I thought, ‘Ah, stuff it, we’re going there – let’s just do it!’”

Stronger conrods and pistons were fitted, too, after a couple of spun bearings had the LS out of the car again.

With an estimated 650rwhp, the Turismo tearer ran a 9.9@135mph at Heathcote during the Holden Nationals. That’s with stock rear leaf springs and spooled BorgWarner diff. “For the money it owes me, I should’ve probably built a nine-inch,” Coco laughs.

It’s not a drag car, though, as the brilliant baby seat shows. Matching the leather throughout the Kingswood – which extends to the neatly trimmed boot – the hand-crafted baby seat means Coco rarely gets to take the HK out alone.

“I had the car before our second daughter was born, so I said to the missus, ‘I’m getting this seat done so it doesn’t look out of place,’” Coco says. “It kind of backfired, because anytime I’d take it out, I’d have to take her ’cause she’d crack the shits if I didn’t!”

Finally, just maybe, that’s a sure sign that this stunning HK is truly complete.


THIS ’64 Datsun pano (above) was Coco’s grandfather’s. Still original with only 50,000 miles on the clock, it’s the one car that’s remained with the family against all odds.

“Dad [above left] was always buying something and tidying it up to sell,” Coco says. “When I was about 13, he built a Morris Minor panel van. Coming home from school, I’d give him a hand. We drove it to Perth for the Morris Minor Nationals, won Top Modified Panel Van, then someone offered him good money for it and he sold it.”

Is the HK on its way out, then? “No. I hated him selling them, so I think I turned out the opposite. The only car he hasn’t sold is that Datsun panel van.

“I had a young fella 12 months ago, and Dad said, ‘You guys have got to keep handing it down.’”


Paint: Turismo Mica 
Brand: 366ci Chevrolet LS2 
Induction: Holley Terminator Stealth throttle body EFI, Holley Hi-Ram 
ECU: Holley Terminator
Supercharger: BDS 6/71 
Heads: LS3 CNC-ported 
Conrods: Callies Compstar 
Pistons: CP Bullet 
Crank: Standard LS2 
Oil pump: Melling 
Fuel system: Aeromotive fuel pump 
Cooling: Aussie Desert Cooler with PWR radiator fans 
Exhaust: Custom Spot On Performance 2in extractors with twin 3½in dual
Ignition: LS2 coils 
Gearbox: Transbraked Powerglide
Converter: TCS with 3500rpm stall 
Diff: Custom 3in tailshaft, full-spool BorgWarner, 31-spline axles 
Front: Pedders 
Rear: Pedders, reset factory leaves 
Brakes: Hoppers Stoppers twin-pistons (f), drums (r) 
Master cylinder: HK 
Rims: Weld Racing AlumaStar; 15×3.5 (f), 15×10 (r)
Rubber: Nankang CX-668 165/80R15 (f), Mickey Thomson ET Street R 255/60R15

My wife Maddie and kids who always support my passion for cars; my brother Rick and dad Peter for getting me into cars at a young age; Spot On Performance & Fabrications in Slacks Creek, Brisbane – the car would not be what it is without them; Danny Lansdowne for the engine build; Ben Mansfield for keeping the paint always looking good; all my mates (too many to list) for help with the car both on little and big jobs