LS3-swapped 1974 Holden HQ Kingswood

Rob Tanti hits a bullseye by transforming a bog-stock Kingswood survivor into the ultimate weekend cruiser

Photographers: Nathan Jacobs

ONE of the biggest challenges of building a pre-1980s muscle car in this day and age is finding a good base to start with. Most examples either look like they’ve been parked next door to the Titanic or require re-mortgaging the house just for a rolling shell. Rob Tanti got lucky in that regard; six years ago he snared a complete and original V8 ’74 HQ Kingswood to use as the base for his dream street cruiser.

This article was first published in the December 2020 issue of Street Machine. Photos: Nathan Jacobs

“I had an HQ One Tonner in my early 20s that I built into a bit of a pro street thing, but I wanted something with more seats to take my mates and kids cruising in,” Rob says. “I got put onto this HQ sedan, which was fully grandpa-spec with a factory 253, column shift, bench seat, mud flaps, towbar, sun visor, hubcaps and even a/c!”

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Rob cruised the Kingswood for a year like that before dropping a second-hand 355 Holden stroker and TH400 in the thing and powdercoating a whole bunch of stuff under the car. He also repainted the engine bay. “I had that driveline in the car for about a year, but it always leaked, and a few other things gave me the shits, so I started looking for something else,” Rob explains.

Rob didn’t touch the outside of the HQ during the build process, opting to keep the original Monterey Green paint in as-received condition. “I think it’s had a paintjob at some point years ago, but it’s the original colour and I wanted to keep it that way,” he says

Initially, Rob was strongly against going modern with an LS, but with some solid persuasion from a few mates, he eventually caved. “I actually hated LS engines, but I saw the potential they have,” he says. “The whole reason I decided to go LS in the end was reliability more than anything else.”

After years of running widened versions of the factory HQ wheels, Rob decided to change it up for a different look. The front Weld V-Series rims measure 17×4.5, while the rear beadlock Weld Vitesses are 15×8 wrapped in Mickey Thompson 255/60R15 radials

With that on the brain, Rob sourced a GM LS3 crate engine to drop in. The donk remains pretty-much stock save for a VCM cam and Manley pushrods and valve springs. It’s the top end where Rob decided to change things up. The factory plastic LS intake manifold was binned in favour of a Holley single-plane, with an Aeroflow throttlebody and Holley EFI fuel rails feeding standard LS3 injectors. “I didn’t like the look of the LS junk; I wanted it to still look old-school even though it’s a newer engine,” he says. Controlling the whole lot is an LS1 ECU with PULP 98 juice, making for a super simple and tough street combo.

Up behind the LS is a fully manualised TH400 transmission sporting a 4200rpm SDE converter, while the rear end was recently given a makeover to match the power from the LS. “I took it to the track on the old widened HQ wheels and street tyres that it had, but even then I didn’t trust the old nine-inch that was in it,” Rob says. A new nine-inch from Geelong Diffs was bolted in with a 31-spline Truetrac centre and 3.9:1 gearset.

Rob wanted the modern LS to look more at home in a classic Holden, so he changed the intake manifold and hid the ugly LS coils out of the engine bay. “It trips some of the older blokes out sometimes; they don’t know what engine it is,” he says

Rob built the Quey himself in his home garage, making sure not to damage too much of the car’s original DNA. “Everything I’ve done is bolt-in and bolt-out; I haven’t cut up any of the original car, which is why it doesn’t have tubs or anything crazy like that,” he says. “Even though I’ll probably never put it back to original, it’s completely possible if I want.”

Amazingly, the cabin is basically the same as when Rob got his hands on the car. The only major change was when he binned the ripped-up vinyl floor in favour of fresh carpet and added the Auto Meter gauges and B&M shifter

The car was completed almost three years ago, and since then Rob hasn’t missed a chance to use it. “I drive it anywhere and everywhere: car shows, family cruises, the lot. That’s why it still has the bench seat in the front, so I can take more people,” he says. “It’s the best thing I have ever done, and I absolutely love driving it.”


Paint: Monterey Green

Brand: LS3
Induction: Holley single-plane, Aeroflow throttlebody
Heads: LS3
Camshaft: VCM
Internals: Standard LS3
Fuel system: Holley EFI fuel rails, in-tank EFI pump
Cooling: Race Radiators
Exhaust: Twin 3in mild steel
Ignition: LS3 coils, ICE leads

Gearbox: TH400
Converter: SDE 4200rpm
Diff: 9in, 31-spline, 3.9:1 gears

Front: Pedders springs and shocks
Rear: Pedders shocks, King springs
Brakes: HQ discs (f), HQ drums (r)
Master cylinder: Standard

Rims: Weld V-Series 17×4.5 (f), Weld Vitesse 15×8 (r)
Rubber: 175/50R17 (f), M/T 255/60R15 (r)

My mate Phil Genio; Chris at Race Wires Auto Electrics for the wiring; Arthur at Tuners Edge; Michael at SDE Converters;
Matt at Geelong Diffs; Race Radiators; John at BBE Automatics; Trevor at TrevTech Automotive; my brother-in-law and my wife for being understanding about my passion