HQ heirloom: the Holden Monaro that is part of the family

How often have you seen seriously cool cars — the owner’s pride and joy — on sale for a steal, with the reason for the sale being something like a big overseas move, an impending divorce, or needing funds for a house deposit? Though a great opportunity for potential buyers, it’s a damn shame for the vehicle’s owner. 

For Warkworth’s Erin Hearne, though, it doesn’t matter what happens — the keys to his beloved 1972 Holden Monaro HQ won’t be changing hands any time soon. Fortunately, Erin hasn’t had to deal with the aforementioned divorce scenario, and his family is now well settled in New Zealand, but what about overseas travel? Well, that’s where Erin’s true passion for this car comes into the story. 

You see, Erin hasn’t always been a Warkworth local; hell, he hasn’t even been a New Zealand local for all that long. Erin is an Aussie, and in 1998 he purchased the Monaro off a security guard, who’d removed the rear seat so he could take his German Shepherd on his rounds.
“It took me two years to get the dog hair out!” Erin laughs — but less funny was the 200km drive home from Wollongong, during which the car went through eight litres of engine oil. Needless to say, it needed a bit of work to get it to the standard at which Erin would be happy with it. 

The car was originally painted powder blue, but Erin planned on changing that. The choice of colour was the source of a great deal of head scratching for a number of years, before Erin bit the bullet and decided to spray the car himself in a golden hue inspired by the Commodores of the early 2000s. It didn’t go well.

“I gave it a quick roller paint in satin black to cover up my shit paint job, and it stayed that way for a few years. Even then, people would give me the thumbs up when they saw it,” Erin explains. 

Unfortunately, Erin’s mother passed away not long after. However, the inheritance gave him the means both to build the car the way he wanted and — knowing he’d never sell the car — to keep a part of his mum with him, rather than have the money absorbed into the mortgage. 
Fully committed to the rebuild, Erin decided on the current colour scheme of black with silver stripes, and the car was stripped for the work to begin. Engine, gearbox, suspension, paint, interior, wheels — they were all improved over the years, and the car slowly became better and better. 

The first, and much-needed, engine rebuild didn’t go as planned. It was, essentially, your bog- standard story about a workshop ripping off a customer it thought didn’t know any better. Since Erin did know better, the next rebuild was to be done properly — and, if he couldn’t trust anyone to do it for him, then he’d just have to do it himself. 

While Erin had toyed with the idea of going for an LS, or some other motor, the appeal of sticking with the original 308 won. It’s a bit wilder than when it left the Holden factory in 1972, though. A Scat stroker kit has been installed, and the block has been relieved to accept the longer stroke, with a Scat crank, Scat I-beam rods, and Hypatec flat top pistons making for a tough rotating assembly. A custom cam with Yella Terra roller rockers and heads ported to L34 spec flows enough air, and is complemented by the 750cfm Holley carb, Edelbrock Performer manifold, and Pacemaker headers. With a compression ratio of 10.98:1, the engine drinks the finest 98 octane petrol and rewards Erin with not only 412hp at the rear wheels but also decent fuel economy when he isn’t giving it a boot up the arse. 

The gearbox needed something serious to handle the huge increase in power and torque. Having busted the original M21 ‘Aussie’ four-speed, and a couple of BorgWarner T5s, the only real option left was Tremec’s TKO600 five-speed. Though an auto would have been cheaper, Erin needs the driver interaction that a manual gearbox gives, and, not only is the Tremec strong enough, it has a great shift action as well. 

The Monaro is definitely a car that has been built to be driven, and Erin doesn’t need much of an excuse to hop in and go for a blat around the countryside. With rebuilt calipers and Hoppers Stoppers rotors all round, the car stops acceptably, although Erin says this is probably the next area he’d like to work on. 

The suspension side of things is more than sorted. Koni adjustable shocks and King Springs super low coils at each corner help to keep the car planted, one-inch front and rear sway bars help it to hunker down around the bends Erin’s so fond of navigating, and a full Nolathane bush kit keeps everything tight and under control. 

Out the back is that rarest of rare things for fans of the old Holdens: a Statesman 10-bolt Salisbury LSD with factory disc brakes. The 3.08:1 final drive ratio makes for a great open-road cruiser, with enough acceleration when it’s needed and the LSD actually a necessity.
“My driveway is really steep, and it’s gravel. Without the LSD, I don’t think the Monaro would make it up,” Erin tells us. 

Erin didn’t always have to contend with a steep, unpaved driveway in the heart of the Rodney district. In 2006, he made the move across the ditch to Auckland, and the car came with him. While he was there, he chipped away at the build and completed a lot of work on the car — until 2009, when he moved all the way to Perth, in Western Australia. Of course, the car had to go, too, and was duly shipped over. 

A year later, Erin moved back to Sydney. He drove the Monaro the 4800km distance, crossing the Nullarbor in the middle of summer, and completing the huge trek in just four days. “I wanted to keep on driving,” Erin says. “I just can’t drive this car far enough to get sick of it or want to get out of it.” 

That’s impressive enough in itself, but it’s only when you consider that the car was a constant work in progress throughout Erin’s numerous trans-Tasman expeditions that the true scale of his dedication becomes apparent. 

Erin moved back to Auckland in 2014, and New Zealand is now home, so this is where the Monaro will be staying. 

“I sometimes think it’s a shame I won’t be able to drive the Monaro in Australia anymore, but I couldn’t be without it. It’s a part of me, a part of my family,” Erin tells us. 

So, if you haven’t guessed from reading this article, we’ll spell it out in black and white: Erin will never sell his Monaro. 

“One day, my daughter will be the coolest chick on the streets with this car,” he says, “but not yet — I’ve got more driving to do first!” 

1972 Holden Monaro HQ

• Engine: Holden 355ci V8, 308 block, Hypatec hypereutectic flat top pistons, 10.98:1 static compression, Scat 9000 nodular cast-iron stroker crankshaft, 3.480-inch stroke, Scat 5.7-inch I-beam rods, ARP 8740 bolts, custom-ground camshaft, Yella Terra roller rockers, Holden L34–spec heads, ported and polished, Holley 750cfm carb, Edelbrock Performer intake manifold, custom air cleaner, twin Unifilter pod filters, high pressure fuel pump, MSD coil, Bosch distributor, Pacemaker headers, 2½-inch twin exhaust, Desert Cooler aluminium radiator, twin thermo fans
• Driveline: Tremec TKO600 five-speed manual, heavy-duty clutch, HZ Statesman 10-bolt diff, 3.08:1 LSD, custom driveshaft
• Suspension: Koni adjustable shocks, Monroe Super Low coil springs, Nolathane bushes, one-inch sway bars
• Brakes: Rebuilt standard calipers, race compound pads, Hoppers Stoppers rotors 
• Wheels/Tyres: 18×7-inch and 18×8-inch Show Wheels, 235/40R18 and 275/40R18 Kumho tyres
• Exterior: Carbon-fibre headlight bezels, blacked-out chrome trim
• Interior: SAAS race seats, retrimmed interior, Momo steering wheel, Auto Meter tacho, Sony head unit, Sony speakers, Sony amp, Sony 12-inch sub
• Performance: 412hp (at the wheels)

This article was originally published in NZV8 Issue No. 124. You can pick up a print copy or a digital copy of the magazine below: