TOOWOOMBA’S James Gardner snagged this HQ at a price he couldn’t refuse. Paying just $5000 for the car in 2019, the 25-year-old first gave the six-cylinder sedan a birthday in the form of a respray in factory white and a neat Eaton M90 supercharger set up.

“I think it went 9.10-seconds over the eighth-mile at the 2019 Six Banger Nats,” says James. “That was the first time I ever raced the HQ. The bottom end was just a stock 202 blue motor with a cam and nine-port head. I think the blower set up cost $250 for a bit of fun.”

The car remained relatively unchanged until Christmas of the same year, when James kicked off a bare-metal, no-holds-barred rebuild.

Out came the venerable 202 that had powered the car for decades, in favour of a stonking Holden V8. A cast-iron 308 block was gifted a Scat stroker crank, bringing capacity out to 355 cubes. I-beam rods hook up to Hi-Tech pistons, topped by early Holden 308 heads – “nothing too flash,” according to Jamie. As a longtime fan of the classic Aussie bent-eight, a small-block Chev or an LS were out of the question for Jamie. “Everybody’s surprised to see an old iron lion in there!” he laughed.

The donk breathes through a Blower Shop 6/71 supercharger, with a Joe Blo EFI kit providing E85 juice. Managed by a Haltech ECU, the injection gear is tucked out of sight for old-school points.

The rest of the driveline consists of a manualised Turbo 400 and sheet-metal nine-inch diff. A Gazzard Brothers set-up occupies the rear, helping to keep the drag radials planted.

Jamie, owner-operator of J-Tune Automotive in Toowoomba, admitted the car’s testing in the lead-up to Drag Challenge Weekend 2020 was limited. “We did about 20km of road-testing before this,” he said. “One week out we put an Aussie Desert Cooler radiator in it, because we found out she gets hot on the highway!”

To keep the car happy and healthy throughout the weekend, Jamie detuned the car to a still-formidable 425rwhp.

He and his crew spent DCW racing in the Haltech Radial Blown class, gunning for a 10-second ET. This proved to be slightly out of reach for the virtually untested HQ, recording a best time of 11.29@120mph across the Willowbank quarter-mile on Day One.

1973 HQ HOLDEN

Class: Haltech Radial Blown

SPECS

Engine: 355ci Holden V8

Supercharger: Blower Shop 6/71

Transmission: Manualised TH400

Converter: TCE 4500rpm

Diff: 9in, 3.9:1 gears

Power: 425rwhp (detuned)

Previous PB: N/A

Best DCW 2020 Pass: 11.29@120mph