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Blown 434-cube 1968 Holden HK Kingswood wagon

By Kian Heagney, 11 Apr 2020 Features

Blown 434-cube 1968 Holden HK Kingswood wagon

Mat Bone's idea of a simply family cruiser is a bit wilder than most, with 434ci of blown Chevy powering his Holden HK wagon

THE phrase ‘the build snowballed’ is one that gets thrown around by car tragics on the regular, but let’s be honest with ourselves for a moment: There’s no such thing as a simple project. For Mat Bone, what was supposed to be just an engine swap on a tidy HK wagon quickly turned into an all-out job, but I’m sure you’d agree the end result was worth it.

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

Holden HK wagon rear

“I bought the car when it popped up in Melbourne because it was a together and driveable Kingswood wagon, running a 307,” Mat says. “So I picked it up and I was going to put a stroked small-block Chevy in it.”

Read next: 355-cube Holden HK Premier wagon 

holden hk wagon side

Mat ended up getting his hands on the 434ci Dart Chevy block currently at home in the wagon, but it needed some help. “It was damaged when we got it, so I took it to James Melmoth at Melway Competition Engines to get it to where I wanted,” he says.

Read next: LSA-powered 1968 Holden HK wagon

holden hk wagon

The Dart copped an Eagle crank, H-beam rods and JE pistons, a custom-grind MCE cam package and a pair of AFR 245 heads for easy breathing. Topping off the whole shebang is the BDS 8/71 blower, fed by 2000cc injectors slotted inside the sneaky Joe Blo hat that pokes its way out of the bonnet. The MicroTech ECU was tuned for both E85 and pump 98, with E85 yielding not only more ponies, but also better reliability. “It runs cooler on E85, so that was the main reason for having ethanol; not so much the power,” Mat says. “I was keen for 1000hp, but on the engine dyno it made 965hp and ran spot-on, so I was happy with that; that’s how it stayed.”

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

holden hk wagon wheel

Mat mini-tubbed the car to allow for chunky 295 tyres on the rear. The 15x5 and 15x9 Weld AlumaStars not only look tough, but also nicely complement the wagon’s Silver Mink duco

The Chev is backed by a Powerglide with a Dominator converter, and a nine-inch rear end sporting 31-spline axles, all of which funnels grunt to 15x9in AlumaStar rear boots.

holden hk wagon engine bay

When Mat got his hands on the car the engine bay was black, which wouldn’t do in a silver car. Anything that wasn’t needed to keep the blown Chevy alive was binned, but the sheet metal remained largely unchanged to keep in theme with the build

Before Mat slotted the fresh donk in place of the original 307ci item, he wanted to get the black engine bay painted to match the Silver Mink exterior. That turned into an extensive exercise. “We took it in to get it painted, but the PPG Silver Mink wasn’t right against the mismatched paint on the exterior,” Mat says. “We figured out the body colour wasn’t actually 100 per cent right, so rather than trying to colour-match the engine bay, I made the decision to have the whole car sprayed in the correct colour.” Dom Stillitano from Hardcore Restorations was given the task of refreshing the HK’s striking silver duco, going above and beyond to achieve a show-quality finish.

Holden HK engine

Before the reassembly process began, Mat had the old green interior binned in favour of a striking new Goya Red layout, but didn’t want to stray far from what Holden had intended in the late 60s. “I didn’t want to put any GTS stuff into it, because it isn’t a GTS; I just wanted to keep it standard with some improvement,” he says. “That’s why it still uses the column shifter for the Powerglide rather than a big ratchet shifter.” The new interior was sourced from Winner Products, using a Premier front bench seat and original Holden hardware where possible. However, when the HK was being put back together, it became obvious to Mat that it was going to need a set of mini-tubs to fit decent-sized rear meats to handle the grunt.

Holden hK wagon cargo

Despite the mini-tubs, the wagon hasn’t lost its practical boot space, still making it ideal for a Sunday picnic cruise with the family

“We fitted the tubs at home very carefully with some help from an experienced mate, and it turned out really well,” Mat says. “It’s a good thing he made room for some extra rubber, because the wagon is still unruly to steer even with 295 tyres in the rear. It doesn’t really go forward when you put the boot into it; it just smokes the rears instead.”

Holden HK wagon interior front

Mat wanted to keep the interior simple, improving on the factory Kingswood fit-out without going for the full GTS replica kit that many get sucked into doing. A colour change from green to Goya Red was all that was needed to give the inside some serious pop

The super-smooth wagon has been finished for around a year now, but it hasn’t seen the light of day much since its completion. “The first time it really came out was for these photos; it’s partly been me keeping the car under wraps and partly a busy work schedule,” Mat says. “It hasn’t been a secret, but I haven’t been very public with the car yet. Now it’s been in the mag, I’ll probably get it out a lot more and just enjoy it with the kids.”

Holden HK wagon dash

Mat doesn’t have any intentions of hitting up the strip with the big beast, opting to keep it to its cruising roots. “I obviously haven’t driven it very far, but when I have it’s driven really well,” he says. “I’ll probably take it to things like MotorEx and enjoy it now.

Holden HK wagon dash

EIGHT TRACK

WHILE it may seem hard to believe now, there was a time when you didn’t have the option of buying a Holden with a V8 up front. The release of the HK in 1968 changed all that with the plucky 307 under the bonnet, kicking off generations of Holdens stuffed with bent-eights until the demise of local production in 2017.

Holden HK wagon engine bay

Needless to say, the blown 434ci Dart Chev in Mat’s HK is a far cry from the original 307-cuber the wagon rolled off the line with all those years ago.

holden hk wagon engine bay

MAT BONE
1968 HOLDEN HK KINGSWOOD WAGON

Paint: PPG Silver Mink

ENGINE
Brand: Dart Chevy 434ci
Induction: BDS 8/71
ECU: MicroTech
Heads: AFR 245
Camshaft: MCE custom-grind
Conrods: H-beam
Pistons: JE
Crank: Eagle
Fuel system: Holley 1600 Dominator pump
Cooling: Aussie Desert Cooler radiator
Exhaust: 2in primaries, 3in system
Ignition: MSD

TRANSMISSION
Gearbox: Powerglide
Converter: Dominator
Diff: 9in, 31-spline axles, 3.7:1 gears

SUSPENSION & BRAKES
Front: King SSL springs, Monroe shocks
Rear: Reset ute leaf springs, Monroe shocks
Brakes: Wilwood discs (f), HQ drums (r)
Master cylinder: Wilwood

WHEELS & TYRES
Rims: Weld AlumaStar; 15x5 (f), 15x9 (r)
Rubber: 195/65/R15 (f), 295/50/R15 (r)

THANKS
Lisa, Akaya and Natika; Brad Simpson; Leigh Haintz; Jason Domaschenze; Ash Hodgson; Barry Hewitt; Dom Stillitano; Nathan Robertson; James Melmoth; Craig Dyson; Rinx

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