AMC reader Chris Sandford found one featured in an old copy of Modern Motor he’d put away in storage. In the July 1984 edition is the HDT Commodore built for prominent motorsport identity Laurie O’Neill.
The photos are in black and white but this car is described as a deep-red VH SL/E Commodore with the original 5.0-litre V8 taken out to 5.7-litre thanks to a billeted Corvette camshaft. Corvette rods and pistons were also fitted.
A mild camshaft made it reliable enough for city driving although it was specifically designed for high-speed touring.
A special four-speed manual and 2.6 ratio diff gave the package a ‘theoretical’ maximum speed of 250km/h and, as tested in road condition, it did the standing 400 metres in 14.91 seconds. That time would have dropped into the 13s with a lower final drive and some sticky competition tyres.
When Brock was asked if the vehicle should be referred to as a Group 3 or perhaps a Group 4, his reply was, “I’d reckon this one’s about a Group 17”. Pure Brock!
That ‘Group 17’ name has stuck.
Laurie O’Neill used the car mainly for interstate trips, so a 90-litre tank was installed. This meant that on a typical Sydney to Adelaide run he’d only have to stop once, at Hay, to fill up.
Fuel consumption on these trips was an impressive 25 mpg.
For the Modern Motor story he loaned the car to former racer David McKay. After driving it for a few days in the city and down the Hume, McKay described it as the modern equivalent to the Phase III Falcon he’d raced at Bathurst in 1971. But with better brakes, he added.
“Yes, the car is a masterpiece of Australian common sense,” he concludes, “and it is ideal for covering our great distances quickly, safely and economically. It would take a well-driven Ferrari or Porsche to keep it in sight; European or American saloons simply need not enter.”
Chris Sandford thinks the Group 17 Commodore could be the ultimate Brockmobile and would be interested to know if it’s still around. So would we.
He knows of another famous Brock special that has survived. This is the black VH ‘Carringbush Special’ produced in 1983 for an unnamed Perth businessman.
Sandford is not sure who owns it today but says it’s alive and well and still in Perth.
This was the 1000th modified Commodore built by HDT Special Vehicles. The package included engine and suspension improvements, aerodynamic aids, bigger brakes, sound insulation, a special sound system and a sunroof. The cost in 1983 dollars was more than $30,000. Laurie O’Neill’s Group 17 Commodore was given an approximate value of $33,000.
Drop AMC a line to amceditorial@chevron.com.au if you own a HDT one-off special.

This article appeared in Australia MUSCLE CAR Magazine Issue 58