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Classical gas: an immaculately completed father-and-son HQ project

19 September 2016


What started as a father/son build has turned into a rolling memorial that would make any dad proud

Four wheels are better than two

In 1996 Nathan Smith and his father were looking for a project. Nathan’s dad was into restoring motorbikes and Nathan had helped him on a couple of his builds. When it came time for Nathan to start a project of his own, he was looking for something a lot larger than a motorbike and with more than two wheels. Having had a couple of HQ sedans in the past, Nathan decided an HQ coupe would be the ideal next step.

 Dad found what they were looking for through the local Invercargill Holden Club. It was an ex-tow vehicle for a drag machine that had then itself been turned into a straightliner. In its drag form it ran a tunnel-rammed 454ci big block, but by the time it got into Nathan’s hands it was just a rolling shell with a trans and diff, a factory interior with a not-so-factory roll cage, and a big hole where the 454 used to be. It looked as if it had seen much better days.

Swedish massage

After purchasing the Monaro, Nathan and his father got straight into stripping it down and getting their hands well and truly dirty. Once the car was relieved of paint it was obvious its years on the strip had been unkind, and a lot of massaging needed to be done to the 23-year-old panels. The rear guards had been flared to fit bigger wheels, but just like the rest of the panels, it was pretty rough. You wouldn’t know it now, though. Every panel was lovingly bashed back to better-than-factory condition and all the seams and lines now match to perfection. 

Even at that very early stage, what was supposed to be a quick paint job and engine transplant was snowballing into a full rebuild.


The engine now residing in the mesmerisingly clean engine bay is a rebuilt 400 Chev out of a jet boat that has been bored 40 thousand over. Eagle pistons and conrods have been fitted, along with a Comp Cams roller camshaft. It has had late-model Chev heads installed, hardened valve seats and Manley valves and push rods with double valve springs. The Holley 750 cfm carb with vacuum secondaries and Edelbrock RPM performer intake manifold ensure enough petrol is dumped into the engine to get the 400 up and running. 

Nathan modestly reckons “It’s pretty mild,” adding, “It’s just a pretty decent street engine, really”. He admits that if he was doing it again he would just buy a crate engine and be done with it. With the jet boat engine, Nathan and his father had to keep going back to the guy they got it from, because everything was shagged in it. 

Nathan’s dad was a perfectionist when restoring motorbikes, a philosophy carried over to the Monaro build. Sadly, 18 months into the work and before the engine was first fired into life, Nathan’s father passed away. Many people would have parked the car up at this point and hid it in the corner somewhere, never to be worked on again, but Nathan wanted to carry on what he and his father had started, as much to build a fitting memorial to his dad as to see the project through. 

Lucky run

After 10 years of building the HQ whenever he was home from working offshore, Nathan was given the one and only task for his upcoming marriage of getting the car finished in time to use as his wedding car. Nathan assured his wife to be that it would be ready in plenty of time — which was some promise, since, when he wasn’t working offshore, by that time he was living in Queenstown and the car was some 200km away in Invercargill. 

Timing is everything, and Nathan’s was impeccable: he was in the garage in Invercargill, still fitting the interior, the afternoon before the wedding. Which was being held in Queenstown… 
After much help from a couple of mates the HQ was finally finished at 6pm. The car had never been road tested, let alone registered, warranted or certified, but there was no time for that. As soon as the final interior panel was fitted it was time to hit the road for the two-and-a-half-hour drive to Queenstown. 

Luckily, everything ran smoothly and Nathan made it to Queenstown with a good 10 hours to spare — enough time, in fact, to give the Monaro a good polish.

Sentimental value

This Fat HQ build started 14 years ago and has been completed for more than three years, but it still looks like it was finished last week. It has not only been finished to the highest standard of workmanship, but also with a timeless style. It combines the clean lines of the body and engine bay with the old-school 15-inch Convo Pro wheels and classic-looking interior, which has been trimmed in light grey leather. There’s almost a factory, late-model car look, with just the right splash of chrome in the roll cage, Quicksilver shifter and billet handles, winders, controls and steering wheel. 

The boot has also been given the custom treatment, with the same ultra-clean style as the rest of the car, trimmed in grey leather with the same perfect amount of chrome as the interior. All the stereo equipment, the battery and spare wheel are hidden behind the custom panelling.
What started life as an easy father and son project, and then quickly snowballed into a full-on rebuild in memory of Nathan’s father, has somehow turned itself into a show-winning vehicle that is driven regularly and which Nathan will never sell. He also tells us that one day he will put a big block in it, just for kicks. We have no doubt that if Nathan’s dad could see how their project has turned out, he would be well chuffed. 

1973 Holden GTS Monaro

  • Engine: 400ci (6555cc) small block Chev bored 40 thou over (408ci/6686cc), Eagle pistons, Eagle H-beam conrods, 10:1 compression, four-bolt mains, forged steel crank, Comp Cams roller camshaft 480 lift, ARP fasteners, Street Master high-volume oil pump, high-energy high-volume oil sump with windage tray, Road Runner starter motor, late-model Chev heads with port job, hardened valve seats, Manley valves and push rods, double valve springs, K&N air filter, Holley 750 Vac secondaries, Edelbrock RPM Performer intake manifold, Edelbrock Performer RPM street fuel pump, 13mm fuel line, billet fuel filter, Delco Remy HEI distributor and coil with Eagle silicone leads
  • Driveline: Turbo 400 trans, trans gear torque converter rebuilt, shift kitted 2500rpm stall, B&M flexi plate, Red Eagle clutch discs, HD intermediate sprag, Remote trans cooler, GM Performance flywheel, shortened Ford nine-inch 3:25:1 gears, limited slip, 31-spline axles
  • Brakes: DBA slotted discs, Bendix disc pads, stock callipers on the front and stock HQ rear
  • Suspension: Pedders Sports Ryder shocks front and back, Lovell Super Low springs front and back, heavy duty sway bars with Nolathane bushes
  • Wheels/tyres: Centerline Convo Pros, 15×6 front with 225/60-15R BFG Goodrich Radial T/As and 15×10 rear with 275/50-15R BFG Goodrich Radial T/As
  • Exterior: De-badged and smoothed locks, Bordeaux Pearl with blue fleck painted by Kingsford-Smith Motor Painting
  • Interior: Retrimmed factory seats in light grey leather, B&M Quicksilver shifter, Auto Meter Ultra-Lite gauges and tach, four-point roll cage, custom door panels, billet door handles, window cranks and controls, custom boot panels, stainless boot lid inserts and ‘Monaro’ logo, hidden Optima battery, hidden spare wheel and stereo equipment, Pioneer head unit, Pioneer 6×9 460W rear speakers and JBL GTO 601 amp
  • Performance: Untested


Driver profile

  • Owner: Nathan Smith
  • Age: 38
  • Occupation: Technician
  • Previously owned cars: HQ Kingswoods, HT ute, a few Commodores – all V8s
  • Dream car: Realistically I have my dream cars; unrealistically a Bugatti Veyron
  • Length of ownership: 14 years
  • Build time: 11 years
  • Nathan thanks: “First and foremost my father for putting in the hard yards at the start of the build, for stripping the car down and spending hours in front of the buffing wheel cleaning parts and never getting to see the car fire up. Dave Morris at Auto and General Sheet Metal, Neil and Bruce at Auto Tech Tuning Invercargill, Darryl Butson at Classic Autotrim Upholstery Invercargill, Peter Pryde at Auto Centre Invercargill, Mike Greving at Invercargill Engine Services”

This article originally appeared in the April 2010 issue of NZV8 (Issue No. 59). Grab your print copy or your digital copy of the magazine now: