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Custom Holden 1-Tonner review

By Mark Allen | Photos: Ellen Dewar, 10 Nov 2018 Custom 4x4s

When three worlds collide, merge, fuse and mutate into one behemoth 4x4 Holden Tonner.

Custom Holden Overlander 1-Tonner feature

“In the beginning, back in 1955, man didn’t know about a rock ‘n’ roll show, and all that jive”… Whoa, that’s one of AC/DC’s legendary riffs.

Take a leap forward a couple of decades, to the mid 1970s when GMH let loose the Holden Overlander, albeit at the hands of a privateer combined with factory manufacturing. In this beginning, we had the option of not only plastic seat covers, grandpa sun visors and rear window venetians, but we could tick the 4x4 options box which provided a fair dinkum 4x4 with high and low range via a Dana transfer case, Dana diffs and the venerable 308 V8. “He said, let there be sound” (AC/DC)… yeehaaa… my kinda rock ‘n’ roll; simple, loud and go hard.

From a young age, I’d dreamt of owning a real Holden Overlander, but had never quite taken my dreams seriously until a couple of short years ago, only to find the rarity of these beasts meant they were hard to find in good condition and prices had skyrocketed.

While full credit must be given to Arthur Hayward for the design and build of the Overlanders, in this day and age, there is, I reckon, a better way to build ’em that didn’t see you riding on leaf springs. After a few talks to engineers and mechanics, I set about sourcing the three amigos of which would become my dream 4x4 – my Mutant Tonner.

I’ll admit to wanting nothing short of a petrol V8 for this build. I would have been happy with an LS1, LS2 or even the old 308, but a phone call from my mechanic, Jason Dymock of Total Care 4WD saw my project jump into the fast lane with the purchase of a statuary write-off VE Maloo R8 Commodore Ute jammed packed with an LS3 (6.2-litre) and 6L80E auto gearbox (six-speed, with tiptronic style shifting).

Holy shittin’ dawgs; I was shakin’ at the knees even thinking about how hard my project would pedal and I hadn’t even heard the deep-throated rumble of the LS engine. What had I bitten off?

Next vehicle procured was a 1990 GQ Nissan Patrol wagon. It seemed there was a glut of cheap GQ wagons up for grabs – and mine was no exception – but I did hold out for one with a 4.2-litre petrol donk, to ensure the preferred diff ratios of 4.11:1 were included. Mine had LPG installed, offering a mid-mounted extra petrol tank that I could utilise as my reserve fuel, while the rear mounted LPG tank would be turfed in favour of a Long Ranger unit.

Extra accessories on the Patrol were simply incidental, as not much would be kept or used, provided the chassis was straight, steering was true and axles weren’t banana shaped. Mine came with two weeks rego allowing me to drive the 400km to Total Care 4WD and before it was deregistered.

Vehicle number three wasn’t so easy. I wanted a Holden 1-Tonner cab and nothing else, no wagons, panel vans or sedans, not even a Statesman. Searching the online sales outlets, asking mates to keep an eye out and even checking out a few car shows returned zero for well over nine months.

I wasn’t prepared to shell out, or pull apart, a big-buck restored vehicle, nor did I want to buy a bare shell from the wreckers, which would return more headaches than it was worth trying to source all the bits and pieces to make it complete.

Persistence certainly paid off; during a visit to the big smoke of Sydney, I again searched through all the online classifieds to find what was to become my donor Tonner. It had been bastardised; originally a HZ chassis, it now sported a HX body and WB front grille and headlights. Even the running gear had been swapped from a straight six with four-speed manual, to a 308 V8 and Trimatic auto box.

The body had been resprayed; it showed only minor signs of rust and it looked perfect with those rectangular WB headlights, albeit dull as candles. After laying my money down, it was driven home and used as a daily driver for six months, while the Maloo and Nissan were stripped and mated together. I lifted the Tonner cab in my side paddock, laid it onto my trailer and delivered it to Total Care 4WD in Sydney for the rest of the custom grafting.

Parts Galore 

HAVING the three cars to strip was one thing; keeping and selling parts to get the most from my investment was another.

The Maloo ended up donating not only the 6.2-litre V8 and six-speed auto, but also the leather seats, shifter, seat belts, accelerator pedal, radiator with dual thermo fans and complete wiring loom – although, that had to be modified. All the rest – hard lid, HSV brakes, side skirts, bonnet, guards and all manner of smaller parts – were sold off returning about three-quarters of my outlay. Not bad, eh!

The Patrol chassis was the underpinning of the whole project, along with suspension, steering, brakes and a couple of smaller items. Everything else was either binned or sold, returning almost 100 per cent of the outlay.

The Tonner cab; wow, haven’t old Holden parts prices skyrocketed of late! Obviously, I wanted the complete cab, along with the whole interior minus the seats. Not more than a couple of days advertising the complete rolling chassis with steering, brakes, suspension, fuel tank, the 308 V8 with Trimatic gearbox and radiator, it sold for my full asking price. 

Separate sales saw the centre console, bucket seats, front bumper bar along with a few other odds and ends sell with an overall recouping of three-quarters of my outlay.

Yeah, I know some will think it’s a sin for pulling apart a seemingly good Tonner … but it wasn’t original, wasn’t a whole car and was made up of a few separate old Tonners – a bastard at best. Plus, in a roundabout way, my sold parts have kept at least three other Tonners on the road.

That engine

Why did I choose an LS3? Yes, there have been a few knockers! There’s a well-worn saying “LS the world” and for good reason. Sure there are other, perhaps, more adept 4x4 engines that could be used – think large capacity, low revving diesels, old school big blocks “if ya want to rev it, Chev it”, or even stick with the ol’ “308, don’t be late”. But, simply, no other engine provides as much bang for ya’ buck as an LS power plant.

They are plentiful, powerful and offer relatively easy fitment given the number of off-the-shelf kits available. While I would have been happy with an LS1 or 2, I got lucky finding and buying a complete written-off Maloo R8 with the 6.2-litre LS3 and six-speed auto. 

Camper, Tourer and Daily Driver 

WHILE the Tonner will get used to drop into the local shops, pick kids up from school and weekend playing in the bush and beach, I also want to go camping and do longer distance touring with it.

Fuel storage was obviously a high priority, so I looked to The Long Ranger in Newcastle which modified its existing GQ Patrol long-range unit to allow for a flat top on which my spare wheel would rest. That gave me 145L, plus the existing mid-mounted tank a further 45L which is transferred via a pump to the rear tank when needed. All engine-used fuel is sourced from the rear tank only.

Every man and his dog are asking: “How much fuel does she use mate?” To date, I’ve not had it long enough to give accurate litres per hundred figures, but can positively say it’s returning 257.5 smiles per gallon – yep, I can’t wipe the smile from my dial. Every time I strap myself in and crank over that engine, my face cracks a grin a mile wide, so, I reckon it’s mission accomplished.

The aluminium checker plate tray with removable drop-sides also incorporates two 3.5-inch stainless steel hoops, of which the rear is removable. Two front-to-rear 3.5-inch aluminium braces (also removable) double as roof rack rails to which my rooftop tent can be mounted, or even a full-length flat tray roof rack.

Initially, I’ll mount a couple of tool boxes into the tray for a little security, but the future may see a canopy or slide-on camper module built. In the meantime, given the tray is so modular and easy to change, I’m expecting plenty of mates to ask for help moving gear around; no problems with me, every chance to take the Tonner for a spin is welcomed!

The starter battery was removed from under the bonnet (a long story of the engineer vetoing my want for twin air cleaners leading into twin snorkels up the A-pillars) and relocated to a chassis-mounted tray behind the cabin.

An additional two Century deep-cycle batteries have been added to the power bank and all controlled by a Projecta DC / Solar charger. This unit monitors and keeps all three batteries topped-up via the alternator while driving and my solar panels while at camp via a 50-amp Anderson plug. The two Century deep-cycles are joined, effectively behaving as one large 200-amp deep-cycle battery.

Driver and passenger comfort is top notch, given the Maloo buckets that have been grafted to the cab. I’ve also used a flat-dish Autotecnica steering wheel on the GQ Patrol steering column to return improved arm reach and comfort.

Keeping me in contact with fellow track users far and wide, a Uniden UH9080 UHF radio mic has been hung on the dash, while the main head unit is tucked away under the dash.

Engineering

My number one want for this project was for it to be 100 per cent engineered, legal and insurable – no compromises.

Consulting with my engineer from day one saw positive outcomes, provided I stick to his rules: no tyre diameter larger than 33-inch, no higher than two-inch suspension and, after some consultation, no twin snorkel.

There is a swag of technical, mechanical and hardware related wishes we conformed to, to allow this project to be ticked off. If you are contemplating anything beyond simple accessories, consult an engineer first and have it all signed off to allow stress-free and safe driving on our roads.

How's it Flex 'N' Crawl?

PATROLS are renowned for huge flex right outta the box. Some delete the sway bars altogether or utilise disconnects to further the axle drop while off-road; both ways improve off-road flexibility, but do little for on-road handling or necessitate stopping to reconnect.

I’ve included a set of Superior Engineering Superflex sway bars, which claim to offer exceptional on-road handling given the larger diameter heavy-duty bar, combined with extraordinary off-road flex with the longer than OE arms.

To say my Tonner drives like a lowered sports car around tight, twisty bends is certainly stretching the truth; but, hell, it handles amazing on the corners! The sway bars are doing their job, but also the low centre of gravity helps to return a fun driving machine; plus the new Terrain Tamer four-wheel disc brakes, callipers, pads and braided brake lines provide amazing stopping power.

Off-road, the Tonner flexes with the best of them, and even when the limits of wheel travel are reached, the front and rear lockers push it farther onwards. Yep, she’s twin-locked, using a manually activated TJM ProLocker in the rear diff, combined with an automatic 4WD Systems Lokka in the front diff.

Of course, having 33-inch Cooper Muddies help with traction off-road by grabbing onto pretty much everything in sight, plus they are not overly noisy on-road for a serious mud tyre pattern and offer reasonable handling on the blacktop.

Should things go pear-shaped, a RUNVA 11,000-pound winch has been grafted into a custom-made cradle hidden behind the ol’ Holden grille. I didn’t want to butcher the grille and we’ve manufactured our own fairlead which is incorporated into the custom-made steel bullbar, which also houses NARVA 215 LED driving lights and wiring loom. The NARVA LEDs were chosen because of the overall slim dimensions to allow fitting the custom bar – plus, they’re damn bright.

Low-range gearing is well suited via the 4.11:1 GQ diff ratios and the 6L80E auto combined with the 33-inch tyres. While not the lowest gearing around, it’s adequate for most uses, although it does tend to need a dab on the brakes while crawling downhill. That’s more the auto box not holding and lack of electronic downhill decent control … bwahaa, who wants that in an old Tonner!

Ultra-slow rock hopping could do with a set of transfer case gears to return lower low-range gearing but all up, it’s a pearler to handle in the slow stuff.

Suspension-wise, I’ve gone simple, reliable, legal and all-round dependable with a set of two-inch raised Tough Dog coils matched to the Tonner’s weight, combined with Tough Dog foam cell, long-travel shocks. While chassis, diff and suspension components clearance is no different to any other GQ Patrol, the way the body has been fitted returns hugely superior approach angles.

How did it all fit together?

SOME parts of this project were ridiculously easy to piece together and we saw massive gains overnight. Other parts however, seemed to take an age of research, trialling and swapping for seemingly no change over weeks and months.

The easy bits were with the aid of a Marks 4WD Adaptor kit. A phone call, a few days wait and the whole shebang was sitting on the garage floor ready for attaching a GU transfer case to the 6L80E six-speed auto, a reverse oil pan to clear the Patrol front axle and diff, engine mounts to fit the LS3 into the GQ chassis, high-mount relocation bracket for the alternator, extractors to clear the chassis rails, cables, pipes and all ancillary gear to make it work, all wrapped into one easy kit.

While initially I opted for a viscous coupling fan setup to be included in the kit, which was designed to fit with a GQ body, we ended up reverting to using the standard Maloo radiator with twin thermo fans because we couldn’t fit the viscous fans in without a custom radiator. Utilising a standard radiator makes an easy replacement if the need ever arises.

Even fitting the Tonner cab onto the Patrol chassis was relatively easy. With complete driveline in place, the cab was lowered down until it touched something, then raised a little and bingo, that’s where it stayed. 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 wiring was pretty straightforward; not to me, but to Sideshows Performance Wiring up in QLD. We sent the Maloo loom to him, he weaved his magic, and retuned it for a (almost) plug-and-play system.

The Maloo Holden traction control, speed sensors, anti-lock brakes and other high-tech wiring has been deleted or blanked off leaving the basics to manage the vehicle. The Maloo accelerator pedal has been incorporated into the system, given it’s a drive-by-wire setup compared to the mechanical cable system of the Tonner.

The hard, fiddly, time-consuming parts to this project are mostly the bits you’ll never see; hidden deep in the guts under the dash for example is a tiny box that converts the electronic speed inputs from the GU transfer case into a mechanical output that spins a cable to drive the original old speedo in the Holden dash.

The output is adjustable to ensure final speed readouts are accurate, which was done on Total Care’s in-house dyno. Might sound easy, but that took an age to sort out given I didn’t want a fandangled digital speedo readout mixed into the rest of the old-style dash.

Trace back the journey of the Holden 1 Tonner project

Bar work

There were no two ways about it; my Tonner was going to sport a bullbar. I didn’t want a huge four- or five-poster job, and it had to be legal. Doodling with pencil and paper saw this final creation of which Total Care 4WD knocked-up from scratch. It also houses the RUNVA winch in a separate cradle, antennae and spottie mounts, recovery hooks, plus incorporates its own fairlead.

Side-steps are three-inch mild steel with alloy checker plate, while rear hoops are stainless steel. Underneath, a steel checker plate bash plate protects radiator and steering arms, as well as helping to prevent water splashing up under the bonnet.

How's it Hammer? 

ON and off-road, it’s fast … bloody fast … dangerously fast, if you don’t control that right hoof. But, driven sensibly, the Tonner is easily used as an everyday driver, along with touring and playing in the dirt, rocks, mud, snow and sand.

My Tonner is the Swiss Army knife of the 4x4 world – the ‘Allterrain Tonner’. While it’s not a comp truck and can never emulate the off-road ability of such, it’s capable of tackling any terrain regardless if it needs to be done at a snail’s pace, ala rock hopping, or with a bit of gusto like in the sand, especially given it’s twin locked and has reasonably good articulation to keep those big Coopers on Terra Firma.

This project has been all-consuming over the last 18 months, caused a few headaches and taken longer than planned or hoped. But, in the end, I reckon I’ve hit the nail on the head in achieving all my goals in style and function, of which I can’t thank Total Care 4WD enough.

After driving this angry, mutant Tonner for the last few weeks, I say again, “LS the world”. To those that claim their 4x4 can go anywhere, I say to you: “So can mine … just f#*kin’ faster.”

Follow the journey of Mark Allen's custom Holden Overlander 1 Tonner 
Part 1
- Part 2
- Part 3
- Part 4
- Part 5
- Part 6
- Part 7
- Part 8