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1000hp LSA-powered 1976 Holden HJ Monaro GTS streeter

By Carly Dale, 19 Jul 2020 Features

Holden HJ Monaro

Despite numerous setbacks, Shaun Dunstan is transforming his cherry-black HJ GTS Monaro into a 1000hp street-and-strip burner

LOW-slung, dark-hued, all-steel big-body, white interior, beefy rims. Shaun Dunstan’s HJ GTS Monaro offers all of this, but also packs hefty horsepower to equal the show-pony looks.

This article was first published in the June 2020 issue of Street Machine

Holden HJ Monaro front

Built in WA, the genuine GTS had done a few shows before Shaun took ownership in early 2019. “I was browsing the internet for 1960s to ’85 Holdens and came across this for sale,” he says of the blown LS1-powered four-door HJ. “I was keen on that shape but I didn’t want an HQ.

Holden HJ Statesman big-block streeter

“Having had a lot of work already done meant it was a great starting point for a build,” he continues. “So I bought the HJ sight-unseen, having been told that the car was in perfect condition.”

Holden HJ Monaro rear

Money was paid and plans were made as the GTS was shipped across the country. “I was so excited that I didn’t sleep the night before the car arrived and was at the depot by 6am,” Shaun recalls. “As I was finishing up the paperwork and standing only a metre away from the HJ, a worker was in the cabin and bumped the wiper switch. He then opened the bonnet and the now-upright wiper ripped along the reverse cowl. It was a terrible sound.”

Castlemaine Rod Shop's LS1-powered HJ Kingswood sleeper

Holden HJ Monaro side

Phil at Lemon Tree Paint & Panel fixed the rust and shipping damage before laying a fresh coat of HOK Custom Candy over the twin-headlight four-door. The final finish is so deep you can swim in it

Unfortunately for Shaun, this was just the start of his woes with his fresh purchase. “Three days later, I was detailing the HJ and I noticed rust bubbles along the doors and other places – it broke my heart,” he laments. “I really should have taken a trip to WA to look at the car before buying it.”

580-cube big-block 1976 Holden HJ Kingswood - MCFRY

But instead of spitting chips, Shaun dug deep to find the cash and motivation to get the body and paint fixed so that he could get on with enjoying his new ride. While finding an old-school panel guy wasn’t straightforward, he eventually came across Phil from Lemon Tree Paint & Panel, who stepped up to tackle the issues. “I dropped it to Phil and said do what you need to do,” Shaun says.

Holden HJ Monaro wheel

A shortened 9in helps to tuck the big ’n’ wide Intro V-Rod 20x10 rears under the guards. “It has basic suspension, though I’m looking to add a drag set-up soon, while keeping it a street car,” says Shaun

Phil got to work on sorting out the body and applying the mile-deep House Of Kolor custom candy paint based on VS Commodore Cherry Black. “Now Phil honestly loves this car as much as I do, and always struggles to give it back,” Shaun laughs.

Blown twin-carb 1978 Holden HZ

Thankfully, Phil had a quick turnaround that saw the HJ back with Shaun within a month. However, not long after, the car copped another massive blow.

Holden HJ Monaro boot

Fashion meets function in the rear, as the leather-wrapped boot trim tucks away the battery and fuel system

“I took my partner Emma to lunch in the HJ, and as we were heading home over a bridge along the highway, the rubber oil return line let go. I had a truck right up my arse and couldn’t pull over without causing an accident, so by the time I could safely shut it down, the LS1 was destroyed,” Shaun says.

Many people would have simply cut their losses at this point, but Shaun chose to look at the dead LS as an opportunity instead of a setback. He entrusted the lads at Zero5 Performance to build the HJ a fresh LSA cratey while retaining the Harrop forced induction. “My plan is to get it close to 1000hp; the motor is built to handle 20psi and 1500hp, as is the trans,” Shaun grins, perhaps a little manically.

Holden HJ Monaro engine bay

While Shaun’s sights are set on 1000hp, he has still kept things show-worthy under the reverse-cowl bonnet, with the factory hinges and hefty original heater all binned in favour of billet parts mixed with Hammertone black and body colour 

The fellas have packed the 6.2-litre with Manley conrods and Mahle slugs, complemented by a Brian Tooley Racing cam and Higgins Race heads. Bosch 2000cc injectors are fed from a pair of Bosch 044 pumps hidden in the boot, while it’s all orchestrated by a Haltech Elite 2000 ECU. Presently the package is tuned to a stout 700rwhp at 12psi.

Holden HJ Monaro engine bay

“The guys at Zero5 have put in a lot of effort to fix up teething issues, and they always have the time whenever I need anything done,” says Shaun. That’s a good relationship to have when you’re chasing big power, and given that Zero5 also has a couple of Drag Challenge contenders in the build, we’d all be stoked if they suggest that Shaun’s HJ tag along for the next event.

“The HJ had previously run a 10.4-second quarter with the LS1, but I haven’t had a chance to go to the track with the new engine,” Shaun says.

Holden HJ Monaro interior

2Tone Motor Trimming in WA swathed cream leather and black suede over the VZ ClubSport seats and HJ door trims, while the factory GTS gauges and tiller remain. A B&M Pro Ratchet shifter helps to bang through the gears. Shaun will be adding his own touches to the interior, too, from billet door accessories through to suede headlining and dash

Now that Shaun – like all of us – has extra time to burn before racing resumes, the GTS will continue to be race-prepped. “I’m adding my personal touches, such as changing the suspension and some of the interior. It will get a rollcage soon, and then I’ll have the dash trimmed in suede – I want to keep it in full street trim,” Shaun says. “At the moment it’s getting Pro Drag rims with 295 radials – I’ll be aiming for nines with the whole new combo.”

It’ll be a top day when Shaun finally gets to rip up the strip in his angry GTS.

Holden HJ Monaro dash

SHAUN DUNSTAN
1976 HJ HOLDEN MONARO GTS

Paint: House Of Kolor Custom Candy

DONK
Brand: LSA 6.2-litre
Induction: Harrop supercharger
Fuel system: Bosch 2000cc injectors, twin 044 pumps and in-tank pump; 2L surge tank
ECU: Haltech 2000
Heads: Higgins CNC-ported
Valves: Stainless-steel, Crow Cams LS dual springs, Manley rods
Cam: Brian Tooley Racing custom grind, LS7 lifters
Conrods: Manley forged
Pistons: Mahle forged, Manley rings
Crank: LSA; Mahle bearings
Oil pump: Manley high-volume, Moroso sump
Cooling: PWR radiator, Spal 12in fan
Exhaust: Di Filippo 4-into-1 extractors, 3in custom stainless dual exhaust
Ignition: MSD coils, Eagle 12mm leads
Power: 700rwhp

DRIVELINE
Trans: TH400, manualised
Converter: TCE 3500rpm
Tailshaft: Custom one-piece
Diff: Shortened 9in, Detroit locker, 3:5:1 gears, Strange 35-spline billet axles

SUSPENSION & BRAKES
Suspension: Pedders SportsRyder super-low coil springs and shocks (f & r)
Steering: LS1 power steering kit
Brakes: Wilwood four-piston calipers (f & r); 330mm discs (f), 300mm discs (r)
Master cylinder: Wilwood

WHEELS & TYRES
Rims: Intro V-Rod; 19x8 (f), 20x10 (r)
Rubber: Pirelli P Zero; 225/40/19 (f), 295/30/20 (r)

THANKS
Phil at Lemon Tree Paint & Panel; Brad, Chris and Matty at Zero5 Performance; my partner Emma for putting up with my passion for cars

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