David Barber’s 1973 Holden HQ One-Tonner – Drag Challenge profile

David Barber's Tonner is a seriously impressive build, with a twin-turbo six-litre LS under the bonnet

Photographers: Luke Hunter, Shaun Tanner, Chris Thorogood

“A FEW people have pointed out that I’m at the wrong show,” laughed WA’s David Barber, pointing to his HQ One Tonner sitting flat on the ground at the Calder Park scrutineering sheds. Dave drove the super-clean two-door commercial to Melbourne from Mandurah, Western Australia, despite it only having racked up 1900 street kilometres before he set off on his 10,000km round trip to and from Drag Challenge 2019.

The Tonner is a seriously impressive build, with a smoothed-out engine bay, custom tray and dash, full AccuAir air suspension and a twin-turbo six-litre LS under the bonnet. Dave actually built the HQ at home in his shed, changing the cowl and sheet metal over to a later HX style, getting a hand from Clive Ross from The Hammer Works helping with the more intricate bodywork before Dave Martin from Martin Brothers Chop Shop laid down the white lick of paint.

The tough LQ4 iron block runs a Lunati cam, deep-breathing LS3 heads, an eBay intake manifold and a stock reflashed PCM, making 680rwhp on just 20psi. Dave bought turbo header manifolds from the USA and mounted a pair of GT3568 snails to them, with a 4L80E trans not only copping all that the forced LS can throw at it but allowing sweet cruising thanks to its overdrive.

Out back, a sheet-metal nine-inch with 3.5 gears lives under the custom tilt-tray and four-linked rear end Dave built himself.

“I’ll be limited to 11s this week, as it isn’t tech-inspected,” admitted Dave at the beginning of the event. “But I’m here to have a go. You build cars to drive them and this is what this event is all about, right?”

Day One saw Dave rock an 11.92@113mph over the Calder quarter-mile, backing that up with an 8.16@92mph and a 7.21@101mph at Mildura in slippery conditions. He continued to improve as he learned the car, running a 7.10@95mph in Portland before going full-send back at Calder on Friday night to finish the week with a PB of 10.66@120mph.

“I actually did a 4500km road trip with my wife and son on the way to Drag Challenge, calling in to see relatives,” Dave said. “That is why the shifter sits on the right-hand side of the seat, as I didn’t want my young bloke kicking the car out of gear as we drove. When we got to Adelaide, they flew home and I kept going to Melbourne.”

Dave was rewarded with a trophy for Longest Distance Driven at Drag Challenge 2019, before he turned around to make the long journey home the next day.


Class: Haltech Radial Blown

Engine: GM LQ4 6.0L
Turbos: Twin GT3568
Transmission: 4L80E
Converter: Stock
Diff: 9in, 3.5:1 gears
Power: 680rwhp
Previous PB: N/A
Best DC 2019 Pass: 10.66@120mph