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434-cube 1968 Holden HK Premier

By Geoff Seddon | Photos: Chris Thorogood, 29 Feb 2020 Features

434-cube 1968 Holden HK Premier

Things are not what they seem on this timeless classic HK Premier from the west coast

IT’S EVERY Holden lover’s wet dream, isn’t it? Finding a pristine, unmolested Premier under an inch of dust in a dry country shed. All it needs is a scrub, a new exhaust and some cool wheels, and Bob’s your long-lost uncle.

This article was first published in the July 2014 issue of Street Machine

Holden HK Premier

Just the right amount of brightwork sets off Matt Harwood’s flawless panel and paint. Tim was initially attracted to the HK for its ample chrome work, to which he added his own fabricated lower grille section. Cars this good don’t come cheap; despite doing everything bar the engine and trim themselves, Tim’s wallet was lightened to the tune of $60,000

Tim Harwood’s HK is not one of those cars. The Perth resident started with just a bare shell in very poor condition; everything else had to be sourced and refurbished. It might look like a restoration, but the list of body mods is as long as they are subtle. Likewise, the stock-looking engine is actually a big-cube monster that goes like a rocket.

Read next: LS3-powered Holden HK Kingswood

Holden HK Premier side

The credit for the breathtaking end result can be shared between Tim and his older brother Matthew, who was responsible for the Prem’s flawless panel and paint.

But the new project got off to a bad start. Once they got the shell home, rough edges were found inside a rear guard, pointing to a dodgy repair. “We had to find a whole right-hand rear quarter before we even started,” Tim says.

Read next: 383-cube Holden HK Kingswood

Holden HK Premier

By his own reckoning, Tim put 150 hours into the subframe alone, removing all the spot welds then seam welding and smoothing in the style of an HQ, with plating for additional strength. The front apron and radiator support bracket are a lso fabricated. It all looks stock until you compare it with a normal HK. “I wouldn’t do it again, that’s for sure,” Tim laughs. “It took a long time.”

Read next: Chev 327-powered Holden HK Premier streeter

Holden HK Premier wheel

The brothers worked on the car for four months, then took an eight-month break while their attention turned to Matt’s wife’s EH. Tim used the time to track down everything else he was going to need to complete the project, including the engine.

“It was going to be a hot 307,” he says. “Then a Dart small-block came up on special. I wanted big cubes; I didn’t want a lumpy engine. It is a show car but I want to drive it. It has to be easy to live with.”

Holden HK Premier exhaust

Engine builder Jason Boyer of CSC Service Centre advised on the spec, which included AFR heads and manifolds. True to the car’s stealth theme and aided by the ‘5 Litre’ badges on the rocker covers, the engine passes for a stocker. “It looks like a 307 but it’s not,” Tim says of his 434-cube, 590hp sleeper. “It’s the exact same colour as the original orange engine paint. There’s no chrome, no bling, no crap.”

Holden HK Premier grille

Unusual these days is Tim’s choice of a Tremec TKO 600 five-speed manual gearbox and adaptor from Mal Wood, driving an Ace clutch and three-inch drive shaft. “Everyone has an auto; I wanted to be different,” Tim explains. “With a manual, I don’t need to run a high stall and fifth is an overdrive. I like the sound of it ripping through the gears.”

Holden HK Premier bonnet

The diff is a shortened VS BorgWarner with 3.77 gears and 28-spline axles. “It was the first mechanical part I bought,” Tim says. “It was out of a VK circuit car that was good for 500hp at the flywheel. It doesn’t rob power like a nine-inch and I wasn’t even thinking of 500hp when I bought it!”

Holden HK Premier fuelcap

Ford stud patterns are employed, which Tim says offered him a better and cheaper variety of off-the-shelf rims to choose from. P76 front brake rotors sit 15mm further inboard, the extra space allowing wider wheels and tyres to be fitted without having to roll the front arches.

Holden HK Premier engine bay

It might look like a factory 60s muscle car but no one ever got 590hp out of a small-block in the good old days. Paint is an exact match for the stock 307, but underneath it’s 434 cubic inches of Dart block and AFR heads filled with all the right gear. The air cleaner shields a monster Holley 950 Ultra HP race carburettor addicted to 98-octane BP unleaded

With all parts sourced, the Harwood brothers got stuck back into the shell in October last year, with Gazzanats in March their goal. Matt focused on panel prep while Tim turned his attention to the interior.

Holden HK Premier engine bay

“It was much harder to bring it back to original than to customise it,” he says. Often it was the smallest things, like the heater knobs, that were the hardest to find. Tyson Cumming from Malaga Trimmers stitched the malt leather in the original style to match the period-perfect interior. New seatbelts were made, also in the stock style – retractable in the front – and the AM radio is standard. The only deviations from stock are Auto Meter oil pressure and water temp gauges under the ashtray, and the elegant leather-sheathed stick-shift. Under the glove box is a Vintage Air replica of a period Mark V air conditioner – as cool as it got in 1968.

Holden HK Premier engine bay

Dynamat sound-deadening has been used throughout – roof, floor, doors, rear guards, firewall, the lot – but hidden from view. The only noise Tim wanted to hear was that coming out of the twin three-inch Pacemaker exhaust pipes.

Holden HK Premier

New front door skins were located but rear doors proved elusive; Matt simply had to rebuild what he had. Door and boot locks were deleted, badge holes filled and the fuel filler relocated to the top of the rear quarter with a motorcycle filler cap. The rear guards were rolled for tyre clearance. A custom front stone tray was fabricated to contain the lower grille section, which Tim constructed from two normal grilles. It looks like it was always there, but see how many other HKs you come across with anything like it!

Holden HK Premier interior

When feasting your eyes on this sumptuous cabin, consider for a moment what Tim started with: not much. A custom or retro-mod dash would have been the easy option, but that would be giving the game away. Tim is considering modern audio innards for the radio and a longer gear lever, now that it’s in regular road use

Matt and Tim work in the family camper trailer business, which conveniently includes a spray booth. Tim assisted with prep before Matt blew on a perfect Dulux two-pack paint job in Mitsubishi Pyrenees Black.

Holden HK Premier doortrim

Apart from a hiccup with a faulty rear screen, this second stage of the build went like clockwork. Having all the parts to hand, ready to fit, was the key. The car was finished in a little over four months and made it to the party on time.

Holden HK PRemier interior

“Gazzanats was its first outing,” Tim says. “We cruised it and entered the show ’n’ shine. We won Top Panel & Paint, out of 250 cars. Matt was pretty stoked; he got second Panel & Paint for his HK too. We just wanted to do the whole thing ourselves, but he ended up beating lots of professionals who paint for a living.”

Holden HK Premier dash

Tim also won Top Four-door Sedan and liked his chances in Top Engine Bay, but fell foul of Gazzanats’ policy of no more than two trophies per car. Not that he’s complaining – it was a great debut and he’s not particularly fussed about chasing more tin now that the car’s on the road.

“I just want to drive it,” he says.

MY BROTHER'S KEEPER

Holden HK Premier

MATTHEW Harwood has been a big influence on his younger sibling; check out the blue HK Premier in the background that Matt’s owned for 20 years. Powered by a high-performance 307 Chev, PREM HK is well known on the Perth car scene as a show car and burnout beast, despite also running a five-speed manual. To see just what a good example Matt’s been setting for his little bro, type ‘Gazzanats 2012 – HK Premier’ into YouTube and see why real cars have clutches.

TIM HARWOOD
1968 HOLDEN HK PREMIER

Colour: Mitsubishi Pyrenees Black

ENGINE
Type: 434ci Chev
Block: Dart
Heads: AFR 210
Carb: Holley 950 Ultra HP
Inlet: AFR
Camshaft: Comp solid
Crank: Eagle, with Clevite bearings
Conrods: Compstar H-beam
Pistons: Mahle
Ignition: All MSD
Cooling: Aussie Desert Cooler
Exhaust: Pacemaker, twin 3in pipes
Power: 590hp at 6000rpm

TRANSMISSION
Gearbox: Tremec TKO 600 five-speed
Clutch: Ace
Diff: VS Commodore, 3.77 gears, 28-spline axles

SUSPENSION & BRAKES
Springs: Kings (f & r)
Shocks: Boge (f & r)
Bushes: Nolathane
Brakes: dba P76 rotors, HQ calipers (f), dba VK (r)
Master cylinder: HK Holden

WHEELS & TYRES
Rims: Center Line Auto Drag; 15x5.5 (f), 15x8.5 (r)
Rubber: BF Goodrich 195/65-15 (f); Maxxis 235/60-15 (r)

THANKS
My brother Matt for panel/paint and everything else; my dad Reg for use of the workshop; Jason Boyer for building the motor; Tyson Cumming for the trim; Dom at Prestige Exhausts, Malaga; MLB Paint Distributors; Todd and Paul at Rare Parts; Brock for fitting the carpet and roof lining

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