Nitrous LS3-swapped HK Kingswood

Ted Bullpitt would be mortified by Jay Jorgensen’s nitrous-huffing, LS-powered HK Kingswood

Photographers: Ashleigh Wilson

There are few things in this world more iconically Australian than a Holden Kingswood. TV’s Ted Bullpitt would have you believe that the humble Kinger is the finest car ever to grace Australia’s highways and byways, but as he’s something of a purist, we’re not sure Ted would approve of Jay Jorgensen’s example. We certainly do, however, and if you don’t mind, we’d like to tell you a little bit about it.

First published in the October 2023 issue of Street Machine

Jay’s HK retains all its OEM brightwork and badging, but the custom Bahama Copper paint provides a modern aesthetic. “The car was white from factory, but I owned a white HQ coupe back in the day, and I wanted something different,” he says

When Jay came to own the HK, it was an original six-cylinder car wearing its factory Ermine White paint, but it was a bit of a mess. It had been disassembled for a resto, so it was the automotive equivalent of a 1000-piece Lego set without any instructions.

“It was all in pieces, with rust in the usual spots – around the windows, beaver panel and lower guards. Nothing too bad, though,” Jay says. “Most of the original Goya Red interior was there and in decent shape, though I did get the front bench redone. I got an old-school local painter to do the custom Bahama Copper paint, then put it back together with the original 186 and drove it around for two years. Then I decided to do the transformation and put a V8 in it.”

Jay nabbed an LS3 as a runner from a local wrecker and had Aaron from ASG Motorsports treat it to a rebuild. Once it was dropped in the car, Jay cruised the Kinger for a while until he melted a piston, so he then had good mate Dan Ward build a forged bottom end retaining the factory crank but adding Spool rods and slugs, along with a VCM 13 camshaft and a set of CNC-ported heads from ASG to spice things up a little.

“I’ve been waiting for a new intake from the States, but I didn’t wanna put one on that’s the same as everyone else’s, so I’ve left the stock one there for now,” Jay says. What you may not have noticed is that, sandwiched between the OEM inlet manifold and fly-by-wire throttlebody, there is a ZEX perimeter-plate nitrous set-up, currently configured to deliver 175hp worth of spray to the LS3 whenever Jay feels he needs it.

To get the engine and trans mounted in the car, Jay opted for a Rod Shop LS conversion kit. “The car has been built for a while now, so this was in the early stages of people doing LS swaps into HK/T/Gs,” he says. “It came in a kit with the engine mounts, gearbox crossmember and headers, which I got ceramic-coated. Doing it that way saved a lot of mucking around.”

A Haltech Elite 2500 got the nod on account of its ability to handle upgrades down the track and run the fly-by-wire throttle, and Aaron has configured it to run the wet nitrous system, too. “You just reach in the window, prime the fuel pump and hit the key; it fires right up and it drives beautifully,” Jay says.

The rest of the powertrain is suitably beefed up, with a manualised Turbo 350 transmission teaming with a Dominator 4500rpm converter to funnel grunt back to a 31-spline nine-inch with 3.89:1 gears and a Truetrac centre.

With a meaty 560rwhp on offer from the chemically supercharged LS3, it was evident that the Kinger’s factory wheel and tyre combo would be a lamb to the slaughter. To that end, the car was set up to accommodate Dumesny 15×8 rear rollers wearing sticky Mickey Thompson ET Street R 255/60R15 hoops, while split mono-leaf springs, Gazzard Brothers traction bars and Koni adjustable shocks further aid traction. At the steering end, the wheels are Weld V-Series 17x4s wearing Mickey Thompson Sportsman S/R front-runners, while Wilwood discs and calipers help to rein things back in at the other end of the strip.

Jay scored the LS3 engine from a local wrecker and had it outfitted with a beefier rotating assembly, a VCM cam, ARP studs, valvetrain mods and a set of CNC-ported heads. It’s mild by some standards, but perfectly streetable, and when Jay arms the ZEX nitrous system, it’ll stomp out a healthy 560rwhp. Even though it’s already handy for bottom 10s at the strip, there might be a Harrop blower in the car’s future

Leaving off the footbrake, the HK has already gone 6.4 seconds to the eighth-mile and 10.2@133mph over the quarter thus far, driven to and from the track. It’s a jet change away from being a nine-second streeter, and that’s quick in anyone’s language.

“My wife reckons she wanted a cruiser but ended up with a drag car, but I disagree; it’s very streetable,” Jay says. “It’s even won a few trophies over the years at events like Harrigans and the Carralbyn Drags show ’n’ shine.”

Goya Red is a cracking factory trim colour on these old Holdens, and fortunately for Jay, his was in pretty reasonable nick when he bought the car. He just had to have the Premier bench retrimmed, replace the carpet and rooflining, and retrim the kick panels. He then added some goodies like the Precision Performance Products shifter and Auto Meter clocks

An Aussie chrome-bumper classic that cruises effortlessly, runs quick at the drags in street trim and can score the odd trophy at a show ’n’ shine is difficult to argue with, but idle hands are the devil’s playthings, so Jay is busying himself with another build as we speak.

“I’m doing a full nut-and-bolt rotisserie build on an HG V8 Premier, as close as possible to factory specs,” he reveals. “I’m doing all the work at home in the shed, only outsourcing the final panel and paint work.”

It sounds like the missus might just get her cruiser after all!


Paint:Custom Bahama Copper
Induction:Factory, fly-by-wire throttlebody
ECU:Haltech Elite 2500
Nitrous:ZEX perimeter-plate wet system
Heads:LS3, ported
Camshaft:VCM 13, 238/242, .603in lift
Conrods:Spool forged
Pistons:Spool forged
Oil pump:Melling
Fuel system:Bosch 044 pumps
Cooling:PWR radiator, twin thermo fans
Exhaust: Twin 3.5in system
Ignition:GM coil packs, 9mm MSD leads
Gearbox:Turbo 350, manualised
Converter:Dominator 4500rpm
Diff:9in, 31-spline axles, 3.89:1 gears, Truetrac centre
Front:King Springs, Calvert 90/10 shocks
Rear:Protrac split mono-leaf springs, Gazzard Bros traction bars, Koni adjustable shocks
Brakes:HQ discs and PBR calipers (f), Ford drums (r)
Master cylinder:Wilwood
Rims:Weld V-Series 17×4 (f), Dumesny with custom beadlocks 15×8 (r)
Rubber:Mickey Thompson Sportsman S/R 26×6.00R17 (f), Mickey Thompson ET Street R 255/60R15 (r)

My mate Daniel Ward for fabbing the sump and screwing together the new bottom end; Aaron and the team at ASG Motorsports for doing the tuning and all the work on this car from day one; most importantly, my wife Courtney for putting up with my constant obsession.