It’s one of t he joys and frustrations of buying a car like an HDT Magnum: tr y ing to work out exact ly what’s underneath t he paint and how many were made. The thing is that HDT, at t he stage t his monster was built, could and would build whatever your litt le heart (and wallet!) desired. So whatever Magnum you own, there’s a good chance it’s just a litt le bit dif ferent to t he one t hat came af ter it. We’re not ta lk ing production lines here.
What’s a Magnum? Essentia lly Brock’s ta ke on a high-performance lu xo tourer. Something t hat would comfortably cross t he continent.
A Holden WB Statesman in DeVille or Caprice form was the starting point. From there HDT would and could do some minor upgrades, but to get the prized HDT build plate you needed to go at least wit h t he suspension and engine modifications.
Exactly how many were built is open to conjecture. HDT’s current owners say the number is under 100, while we’re hearing under 120 from ot her sources. ‘Not a lot’ is correct.
The car you see here is a ver y good example of what you’d get if you went t he ‘f ull monty’ wit h t he HDT cata log ue. To start wit h, t he 5.0lt engine was upgraded to Group 3 specs, which meant a huge 50 per cent lift in power from 126 to 188kW (169 to 252hp).
That was achieved with a Quadrajet carburettor (‘blueprinted’ if you ticked t he appropriate option) mated to a cold air inta ke, a dif ferent inlet manifold, bigger va lves, a ltered combustion chambers and a 9.2:1 compression ratio. The transmission was a beefed-up Trimatic and you probably would have been well-adv ised to run t he optiona l transmission cooler and perhaps t he engine oil cooler as well. To cap it of f, you could specif y a 3.08 ratio limited slip dif f, which is on t his example.
As for t he chassis, t hat received a lot of attention, too. The whole car was lowered substantia lly, and f itted wit h reworked Bilstein dampers, dif ferent rate springs, beef ier roll bars, a ll in addition to a ltered geometr y. That was completed with a Momo steering wheel.
The car a lso sat on (assuming you ordered t hem) 16 x 8-inch a lloy wheels, running Pirelli P7 rubber.
As for cosmetics, you could mix and match whatever Holden offered across the Statesman range, while HDT could add its own touches such as changing the bright work for colour-coded trim plus tinting for t he windows and lights.
Fully k itted-out, you could easily end up spending mid $30-thousands on what would undeniably be a ver y specia l car. It was a lso about half t he price of a house !
The example you see here belongs to Neil Peck and has proved to be an award-winner at assorted shows, not least of which was
last year’s huge Brock anniversar y gat hering at Mount Panorama and run by the Brock Commodore Owners (bcoaa.com).
Neil’s search for t his car began some time ago. “I’ve got a couple of friends who own Magnums,” he explains. “I decided I wanted one. I hunted around for quite a few months, rang the guy about this car, which was in Queensland, got a ll t he histor y, and rang his mechanic. We did the deal over the phone. Within a week it was at my house. That was 10 years ago.”
The Magnum turned out to have a great histor y. It was ordered as a showroom display car by Zupps – then and now a huge dealer in Brisbane – and came with prett y much a ll the paper work you could hope for. For example, t here’s a copy of t he sign-of f sheet from Peter Brock, who took it for t he test drive before it lef t t he factor y. “Good rig. Nice,” he wrote.
Subsequently, t he car’s owner took it to t he Brock Shop in Queensland to be ser v iced, where one of t he ser v ice sheets was signed off by Phil Brock.
In case you were wondering, yes, the Brock touches make a welcome difference to how the car drives. We had a litt le steer of it af ter t he photo shoot. For something that size from that era, it’s an impressive rig. It points well and ta lks to you, keeps a nice f lat attitude t hrough corners and has plent y of grunt. You can well imagine t hat whoever f irst bought t he t hing would have been prett y damned pleased the f irst t ime t hey cut it loose.
These cars only pop up on the market occasiona lly and t here is a lot of variation from one to another. If you were in t he hunt, you’d easily be look ing at $ 30k as a sta rting point for a well-specced solid example that was in need of a freshen-up, and we reckon you would go a ver y long way nort h of t hat for a rea lly good example. Will we soon see $ 50k? Quite likely...
TOP RIGHT Performance upgrades were serious, giving a 50 per cent lift in power.
CENTRE RIGHT This is an early pattern wheel and only six sets with the flutes are thought to exist.
ABOVE Owner Neil Peck.