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LS-powered 1973 Holden HQ Kingswood wagon

By Dave Carey | Photos: Nathan Jacobs, 27 Oct 2018 Features

LS-powered 1973 Holden HQ Kingswood wagon

Andrew McQualter's 202-powered inter-pub cruiser copped the LS treatment big time but along the way there was plenty of blood, sweat & beers

This article on Andrew's HQ wagon was originally published in issue no.7 of Street Machine's LSX Tuner magazine, 2018

ANDREW McQualter is an HQ man through and through. His fleet comprises five of the 485,000 HQs that GM-H built. Two utes, a worked GTS sedan, his missus’s Kingswood cruiser and an unrestored Barbados Green snotbox wagon complete the set, but the big surprise is which one packs the most horses.

Holden HQ wagon“I bought the wagon off an 83-year-old gentleman,” Andrew begins. “It had been a CSIRO fleet car and had never been in a prang. I cruised it around with the 202 as my brewery weapon.”

The wagon didn’t need horses; that’s what the GTS was for, pulling mid-10s at 130mph from a 355 stroker motor.

Read next: Twin-turbo L33-powered 1970 Holden HG wagon

Holden HQ wagon sideAndrew’s plan to build the LY6 once and build it right is noble, but he also had to think about the coin. The LY6 block came up on Facebook, located in Brisbane and part of an unfinished project that was being broken up. “I ended up with a lot of parts like that, brand-new second-hand stuff off Gumtree and the like,” he says

“The GTS was full of decent gear, but one pass I put just a bit too much gas through it and hit all eight pistons against the heads,” Andrew says with a wince.

Knowing that an LS would do the job easily, but not wanting to meddle with the genuine GTS too much, Andrew’s attentions turned to the pub cruiser.

Watch next: Slammed custom Holden HQ wagon - video

Holden HQ wagon“I’ve got mates with HQs, like Rodney Browitt with NOCOIN, but none of them had turned out a really fast wagon.”

So with attentions turned to the original Barbados Green family goonage, Andrew flicked the Holden red motor, grabbed a set of Castlemaine Rod Shop mounts, a modified Turbo 350 crossmember, and pretty much plonked a mystery donk straight in. You can get lucky with a wrecker-spec LS1, so Andrew mated it to a stock ECU and Chinese turbo, then took it for a drive.

Read next: Procharged LS1-powered Holden HZ wagon sleeper

Holden HQ wagonWhen the first LS let go, not only did it throw a leg out of bed, but blew the intake manifold and popped the bonnet, folding it back into the windscreen. Although showing the appropriate battle scars for a 45-year-old car, Andrew couldn’t leave the bonnet like that. “Yeah, nah, I fixed it with a mallet!” Patina bliss!

“We got a couple of kays down the road and I was in top gear for all of a few seconds,” he recalls.

Unfortunately, the HQ didn’t come with a ‘danger to manifold’ warning light and the whole thing went ‘bang’ in a serious way; a rod pierced the block.

Read next: Family heirloom 1968 Holden HK wagon

Holden HQ wagon wheelBuying an old car off the original owner is getting harder and harder, but when Andrew bought his Barbados Green HQ wagon in 2013, he got the works. “It was on Gumtree for about five minutes!” he laughs. “The old guy didn’t seem to understand that I was coming to buy it, not coming to look first. When I got there with a trailer, he took me in the house and offered me tea and biscuits!” We’re not sure old mate would approve of the mods, but Andrew’s lost his details so hasn’t gone back for a visit. That might be a good thing

“The intake pipe blew itself off and it even popped the bonnet latch,” Andrew laughs. “The bloody thing flipped over the windscreen; I had to drive like Ace Ventura until I could pull over.”

A shit experience turned into a hoot of a story, but hoots don’t munch quarters. Although the car was relatively well set up for another LS1, Andrew sold the whole set-up and started again.

Holden HQ wagon boot“I knew I wasn’t going to stuff around again; I would buy the best parts I could, but wanted to do a heap of research first,” says Andrew, a sparky by trade.

He hit up the Google, studying other set-ups and checking out what worked and what didn’t.

Holden HQ wagon bootThe roof racks, venetians and stock steelies showing just a hint of dish at the rear give the HQ a decent level of sleepiness. For racing duties, Andrew throws on a set of Weld Draglite rims measuring 8.5in at the back and ditches the bench for a pair of RCI race seats and harnesses. “The race seats bolt into the factory holes, actually,” says Andrew. “But it’ll need a ’cage and tubs soon enough”

“I knew I wanted an LY6; it’s an LS3-based truck motor in cast iron," he says. “Square-port L98 LS3 heads just bolt straight on.”

Hitting up mate Rodney Camilleri from Precision International, together they sussed what Andrew could get off-the-shelf that would get them close to the 1000hp target.

Holden HQ wagon engine bayThe engine bay is as business-like as it gets, with coil-packs, wiring, leads and the like all pretty much in their stock locations. “I wanted it to look as standard as possible, but neat,” Andrew explains. Having studied up to get an idea of which off-the-shelf items would yield bulk horses, he came to the realisation: “Once you start moving stuff unnecessarily, you’re spending money you don’t need to”

Rodney calculated the ideal compression and suggested all the engine internals to suit, but the responsibility for screwing it all together fell to Paul Burger at North Eastern Head Repairs in Wangaratta. Although he’s known more as a 308 Holden engine guru, Paul clearly has the skills across the board.

“He built my 355 stroker, which was a good unit until I stuffed it, so I was happy for him to build this one,” says Andrew.

Holden HQ wagon engine bayPaul bonked a set of CP-Carrillo Bullet-series pistons into the factory-fresh LY6 block, using Hastings rings to ensure the explosions don’t slide down the cylinder walls, while King Race Series bearings ensure the lot spins freely.

The use of 6.4-inch Lunati H-beam conrods was Andrew’s contribution.

Holden HQ wagon engine bay“A lot of people use 6.125-inch rods, but they only allow 3-4° of dwell time,” Andrew explains. “Thinking like a sparky, I figure that the longer the rods, the longer the dwell time; 9-11° gives the E85 more time to burn.”

Despite all the heavy-duty gear, Rodney recommended a stock LS1 crank, believing it to be more than up to the task. Up top, standard valves bounce off a Camtech 233/244 cam by way of Crow chrome-moly pushrods and standard LS3 lifters, and are controlled by Camtech heavy-duty valve springs.

Holden HQ wagon interiorWhen Andrew’s wife Kim announced a few years back that she wanted to go to Summernats, Andrew resisted. “I said it was a boys’ weekend. Next thing I know, she’s bought tickets before me and organised a pile of girlfriends to go with her!” Kim, who featured in Street Machine’s Iron Maiden section a couple of years back, spends the time cruising in her 202-powered HQ Kingswood sedan. “She does her thing, I do mine; the only time I ever heard from her was when she had the gearbox jammed at a servo and wanted me to come and un-jam it!” he laughs

Andrew installed the engine, sitting the LY6 on a set of Tuff Mounts, but not before rebuilding the steering and front suspension, and blasting the ’bay in a coat of GM Chassis Black. The V8 is backed by a fresh transbraked Powerglide by Burko Transmissions in Shepparton and runs a sensible 3600rpm stally from Pro Converters in Dandenong.

Andrew shoved a narrowed nine-inch built by Shaun McCarroll Diffs up there at the same time, and wired up the Holley EFI system over many shed beers.

Holden HQ wagon dashWith the wagon nearing completion, he shipped it to Darcy Stafford at KillaBoost for turbo plumbing and fit-up, plus an off-the-shelf Plazmaman Pro-series intercooler. Jeff Johnson from STREETBUILT Racing handled the start-up tune, and Luke Spalding at LS Tuning & Performance Centre strapped it to the rollers for a proper tune.

“The Holley system is so easy; once it’s running, it starts learning,” Andrew says. “After each run I checked the datalogger and updated the fuel table manually.”

Holden HQ wagon dashAndrew cut out the wagon’s underfloor rear pan and had a mate fold up a new, sunken tray to accommodate the off-the-shelf RCI 63L fuel cell and twin Walbro 460 fuel pumps in the surge tank. “I did it so it would look factory when you looked in the back of it,” he says. “And when I get it ANDRA-complied, hopefully they’ll class it as a separate, sealed fuel compartment”

After four runs, the LY6 was turning out over 700hp.

“It just started running better and better; pretty soon it was showing 909hp and 1878Nm,” Andrew says with a grin. “All it wanted to do was spit the dyno out behind it!”

Holden HQ wagon gearsWith the HQ wagon standing right up on the front roller, the boys strapped it down at the front, but to no avail.

“It was a bit of a battle, actually, but really good fun. We left it at 18psi and that’s still about where it is. I’d like to push it up to 26psi and see what happens!”

Although Andrew concedes the ’Q will need a hub-mounted dyno to see more accurate readings, it didn’t stop him from entering Horsepower Heroes at Summernats 31.

Holden HQ wagon ignitionAndrew had problems starting it for the first time; so much so it almost cracked his brain. “I’d painted the block black and painted over my crank angle sensor, changing it from cream to black,” he says. The problem was his use of a 24-tooth reluctor wheel. “The new crank angle sensor was already black, so I just assumed I’d put the new one in. Everyone said that could’ve been the problem, but I ignored them. When I worked it out, I went: ‘You dickhead!’” 

“I’m not a dyno guy,” he says. “I was just sorta driving around Summernats and thought that we may as well throw it on there; we’d just be drinking beers and being dickheads otherwise!”

Holden HQ wagon onroadDespite no special tune, the LY6 returned 845hp, good enough for fourth place in the V8 Blown class and an ‘Outstanding Performance’ trophy.

Andrew’s ultimate goal is to ’cage and tub the wagon, then chuck it down the quarter. He’s keen to compete in Street Machine Drag Challenge, but for now is just happy being on an even keel with his missus, Kim.

“She was covered in Iron Maiden a couple of years back and has given me heaps that she’s been in Street Machine and I haven’t!” he laughs. “Gotta thank her, though; she’s been a great support and massive help.”

Andrew McQualterANDREW MCQUALTER
1973 HOLDEN HQ KINGSWOOD WAGON

PAINT
Barbados Green

ENGINE
Type: Chevrolet cast-iron LY6 
Capacity: 373ci
Intake: Stock
Induction: Nick Williams 92mm
Turbo: BorgWarner S488
ECU: Holley HP EFI
Injectors: Bosch 1700cc
Heads: LS3
Pistons: CP-Carrillo Bullet
Crank: LS1
Rods: Lunati H-beam
Cam: 233/244 Camtech
Pushrods: Crow chrome-moly
Lifters: LS3
Valve springs: Camtech
Valves: Standard
Oil pump: Melling high-volume
Ignition: Holley EFI HP
Fuel pump: Holley 150 lift, two Walbro 460s
Exhaust: 4in dump pipe, 4-into-1 headers, Hooker 4in muffler

TRANSMISSION
Transmission: Transbraked Powerglide
Converter: Pro Converters 3600rpm stall

SUSPENSION & BRAKES
Brakes: Wilwood discs with four-spot calipers (f), standard drums (r)
Springs: HQ six-cylinder (f), HQ race series (r)
Shocks: Competition Engineering 90/10 (f), Competition Engineer 50/50 (r)
Steering: Rebuilt HQ
Rear end: Shortened 9in
Diff: Strange Pro Series 9in iron case, Strange billet yokes and pinion supports, US Gear 3.55:1 gears, Moser axles and Pro9 adjustable control arms
Tailshaft: Custom 3in chrome-moly

WHEELS & TYRES
Rims: Road – HQ steelies; 14x5 (f), 14x8.5 (r) Racing – Weld Draglite; 15x4 (f), 15x8.5 (r)
Rubber: Road – Olympic Sprinter 225/65/14 (f & r)  
Racing – Maxxis 165/80 R15 (f), Mickey Thompson 255/60 R15 radials (r)