MONSTER V8-powered SUVs are all the rage in new-car land these days, but a Tasmanian bloke called Arthur Hayward was right onto the concept 45 years ago. Arthur took brand new Holden utes, vans and wagons and transformed them into off-road weapons dubbed the Overlander.

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

The Overlander was no backyard job, and started with brand-new vehicles only – at least until Holden stopped making the donor cars. While GM-H made Arthur buy complete cars, they honoured their warranties, giving the project a factory-approved sheen.

Arthur later added wagons to his product list, providing an affordable alternative to the Chev Blazers and Range Rovers of the day. In total, 120 Overlanders were built, and attracted a cult following that included a young petrolhead named Mark Allen.

A 145L Long Ranger fuel tank at the rear of the truck combines with a 50L reserve tank mounted amidships to give 195L capacity. The spare tyre fits neatly on top of the main tank. The front flares are genuine Overlander items

“I’ve always wanted one,” says Mark. “But I only got serious about it a couple of years ago. By that time, the rarity of them meant they were hard to find in good condition, and prices had skyrocketed. So I decided to build my own version.”

While the original Overlanders were built using a bespoke front chassis grafted onto the Holden unit, matched to specially imported Dana diffs and transfer cases, Mark opted to instead employ a complete ladder-frame chassis from a 1990 GQ Nissan Patrol, along with its coil springs, live axles and GU transfer case.

“The GQ was an easy choice for many reasons,” says Mark. “The chassis is easily strengthened, the coil springs deliver a major improvement in on-road performance, and they provide an incredibly adaptable base that is easily modified from mild to wild.”

A custom steel bullbar replaces the factory bumper and houses the driving lights, antennae and recovery hooks, and also provides access to the Runva 11,000lb winch that is tucked up neatly in a cradle behind the WB grille

The second part of the puzzle was the purchase of a statutory write-off VE Maloo R8, which yielded a 6.2-litre LS3 and 6L80E six-speed auto, as well as leather bucket seats, radiator, retractable seatbelts, wiring loom and accelerator pedal.

Finding the Tonner cab itself was the toughest job. The one Mark eventually chose was a typical grandpa’s axe: an HX cab sitting on an HZ chassis, with WB headlights and the original six-pot driveline swapped out for a 308 and Trimatic.

The stock LS3 provides more than enough herbs to get Mark in trouble. The high-mount alternator was necessary to clear the Patrol driveline bits below. Mark wanted to run dual snorkels, but the engineer vetoed them in favour of a barrel intake hidden behind the driver’s-side headlight

Nevertheless, Mark says it was a good unit: “It only had minor signs of rust and looked perfect with the WB headlights. I drove it home and used it as my daily for six months, while the Maloo and the Patrol were stripped and mated together by Total Care 4WD in Sydney.”

Meanwhile, Mark got busy selling off the unwanted bits from his three donor cars, making back 75 per cent of the purchase price on both the HX and the Maloo – and almost 100 per cent of the Patrol!

And the mating itself? Mark reckons this unholy three-way came together quite nicely with a bit of research. A Marks 4WD Adaptors kit took care of the bits needed to slide the LS driveline into the Patrol chassis, including attaching the transfer case to the six-speed auto, a sump that would clear the Patrol axle and diff, engine mounts, high-mount alternator relocation bracket, extractors and more.

The Tonner runs three batteries, all located under the tray: one to start the car and two Century deep-cycle units. A Projecta DC/solar charger keeps all three batteries topped up via the alternator while driving and by solar panels while at camp

“Even fitting the Tonner cab onto the Patrol chassis was relatively easy,” says Mark. “With the complete driveline in place, the cab was lowered down until it touched something, then raised a little, and bingo – that’s where it stayed. The standard GQ chassis-to-body mounts were removed and repositioned to suit the Tonner cab, plus a couple of extras added for good luck and to appease the engineer.”

The fact that the Tonner is registered as a 1990 Patrol meant that a classic GTS steering wheel wasn’t going to cut the mustard with the engineer. Instead, Mark went for an ADR-approved Autotecnica Racer Pro tiller, mated to the Patrol adjustable steering column. The seats and belts are ex-Maloo, while air con is Vintage Air, mated to an LS1 compressor

With the three vehicles made one, the rest of the build was about optimising the Tonner for long-haul, off-road adventures with the addition of 33-inch Cooper muddies, manually activated TJM Pro Locker rear diff and an automatic 4WD Systems LOKKA in the front diff.

Superior Superflex sway-bars help the Tonner deliver a decent compromise between on-road handling and off-road flex. Terrain Tamer four-wheel discs bring the stopping power up to scratch. Springs are two-inch raised Tough Dog coils, combined with Tough Dog long-travel shocks.

And how does it drive? “On and off road, it’s fast – bloody fast,” says Mark. “Driven sensibly, the Tonner makes a great daily driver.

“Off road, it’s capable of tackling any terrain, regardless of if it needs to be done at a snail’s pace, such as rock-hopping, or with a bit of gusto, like when it’s in the sand. The project took an all-consuming 18 months, but I reckon we’ve achieved all my goals for a modern-day Overlander, and I can’t thank Total Care 4WD enough.”

MARK ALLEN
HOLDEN HX ONE TONNER

Paint: White

ENGINE
Brand: 6.2L LS3 V8
ECU: Factory with MAF-less tune
Internals: Factory
Exhaust: Marks 4WD Adaptors headers, custom 3in into 2.5in exhaust system

TRANSMISSION
Gearbox: 6L80E auto, Tiptronic shifters
Transfer case: GU Patrol
Diffs: Nissan Patrol, 4.11:1 gears, TJM Pro Locker (r), LOKKA diff lock (f)

SUSPENSION & BRAKES
Front: Nissan Patrol three-link with GU leading arms, Tough Dog 2in-raised springs, Tough Dog foam cell shocks, Superflex HD sway-bars
Rear: Nissan GQ Patrol five-link, Tough Dog 2in-raised springs, Tough Dog foam cell shocks, Superflex HD sway-bars
Brakes: Terrain Tamer discs (f & r)
Master cylinder: Commodore twin-diaphragm

WHEELS & TYRES
Rims: Dynamic steel 16×8 (f & r)
Rubber: Cooper STT PRO 285/75R16 (f & r)