Blown big-block 1970 Holden HT Monaro GTS – 1FATHT

Brett Hewerdine's killer blown Holden HT Monaro put the 'Tuff' in Tuff Street at Summernats 32

Photographers: Chris Thorogood

WITH thousands of comments and many thousands of shares, this HT Monaro nearly broke the internet when images of it surfaced in the lead-up to its debut at Street Machine Summernats 32. When it hit the cruise route, the hype wound up past 11!

This article was first published in the April 2019 issue of Street Machine

“Paul and the crew from ProFlo Performance had been thrashing for 10 weeks to get it done – and we only just made it,” says the car’s proud owner Brett Hewerdine. “Every time we cruised, the crowd would start chanting for me to do a skid. But with the car so fresh and the concrete barriers so close, I didn’t want to tag the wall, though it was mighty hard to resist the temptation. And to be honest, even though I’ve had it out a number of times since then, it still scares the shit out of me – it’s quite intimidating. Sure, I’ve had tough cars before, but this is next-level!”

“It was about 70 per cent complete when we got it,” says Paul Sant. “We gutted it back to a bare shell, then started at the back and worked forward – all in 10 weeks. There was so much old stuff that needed updating”

That’s hardly surprising, considering the Big & Ugly hat perched atop the 14/71 Littlefield pump, which pokes out of the bonnet and force-feeds 510 cubic inches of Donovan big-block below. The engine originally came out of Paul Cannuli’s ski boat. It was built by Bluey – the same guy responsible for the engines in Paul’s PC Cranes Doorslammer.

“It made 2000hp!” Brett says. “Paul drove it like a lunatic, scaring the crap out of everybody who rode in it. There were even a few nutters game enough to go for a ride in a tube behind the insane machine.”

As fate would have it, Paul was looking to offload the engine and Brett was after something that would make a statement – done!

As you’d expect, the blown street beast gets a reaction every time Brett takes it out. “You should see the look on people’s faces when I’m out cruising and pull up next to them at the lights!” he says

However, let’s stop there a moment and rewind, as there’s quite a back-story to this epic Monaro.

As it turns out, Gretchy from ProFlo owned it many, many years ago. From Gretchy it went to Sash, who on-sold it in about 2010 to Brett’s close mate, Simon Rasic (read more below).

“I first saw it in around 2012,” Brett says. “Simon had been building it for a few years and it had just come back from Angelo’s Cool Customs, who did the bodywork and painted it black. Simon actually tried to sell it to me back then. I told him no, as I was in the middle of building my ’37 Ford.”

At this stage John Cannon at JC Fabrications had back-halved the coupe, did the tubs and fitted a traditional four-link. It had wide Draglites, a blown small-block and twin fours. Very early on, it was being built as a full-on drag car – with a full ’cage. Wanting it to be more of a street car, Simon cut out the front half of the ’cage.

Paul Sant from ProFlo Performance picks up the story: “That’s how it came to us. It was a real 80s-style pro streeter that was about 70 per cent complete. We gave it the ProFlo treatment!”

The ‘treatment’ included chopping out the old four-link and fabricating a completely new set-up. They also re-engineered much of the existing chassiswork to enable the car to sit waaay, waaay down low.

The re-engineering didn’t stop there. The ‘tough-as-muck’ ride height meant the tunnel had to be raised, a new gearbox crossmember fabricated, and channels cut into the floor to accommodate the twin 3.5-inch exhaust system.

To give Brett’s HT a decent range on E85, ProFlo added a 130L fuel tank. The huge tank and massive tubs pretty much fill the entire boot. Also hiding in there are the electric power steering pump and transmission cooler

Up front, a Rod Shop double A-arm, coil-over front end was narrowed 60mm per side to pull the tyres inwards, giving them room to turn. The factory disc/drum set-up was never going to cut it. ProFlo upgraded it to a full Wilwood system, including master cylinder, six-piston calipers up front, four-piston calipers out back, and new plumbing throughout.

Those monster front brakes necessitated stepping up to 17-inch wheels, while at the blunt end, the HT is now chock-full of 15×14 forged Welds, wrapped in wider 18.5-inch Mickey Thompson Sportsmans.

The blown, injected 510ci Donovan donk came out of Doorslammer racer Paul Cannuli’s boat – and made around 2000hp on methanol. To make it street-friendly, it was reconfigured to EFI with a Haltech Elite 2000 for smarts, then Adam Neish from Just Engine Management re-tuned it for an effortless 700hp on E85

With loads of grunt up front and grip galore at the rear, all the bits in between needed to be equally burly. Sash from Marko Transmissions screwed together a bulletproof, full-manual TH400, while ProFlo weighed in with a chrome-moly tailshaft before filling the very narrow nine-inch with a Strange alloy centre, street-friendly 3.55:1 gears and 35-spline Detroit Truetrac.

Under the hood, a host of redundant holes were welded up, the engine converted to dry-sump and a huge Shaun’s Custom Alloy radiator shoehorned between the fenders.

“At first it cruised fine, but didn’t like traffic lights,” says Brett. “She’d get a bit hot. Fitting a third thermo fan fixed the issue – it’s all good now.”

With the clock ticking down to Summernats 32 in January, plans to respray the Monaro’s black outer coat had to be put aside for a later date.

“Having sat around for so many years, as well as having stuff piled on it, the paint was looking a bit tired,” Brett says. “We would have liked to repaint it, but there wasn’t time. With ProFlo being so busy, it was only 10 weeks ’til Summernats before I was finally able to get it into their shop – and I really wanted to make Summernats.”

Nonetheless, Anthony from Anthony Caronna Custom Bodyworks painted the engine bay, boot area and undercarriage. In the end, everybody was blown away at how good the now seven-year-old paint came up with a good cut ’n’ buff – win!

While retaining the GTS door and side trims, the car came sans dash, with Brett having to source a replacement. Unhappy with the existing seats, he had Darren Baldwin from Stitched Up Custom Trim strip them down, fix the springs and re-foam them for more support. Now you sit in them rather than on them – much better. On New Year’s, Steve Maiolo from Alltrim came to the rescue with a last-minute rush on custom-mould carpets to accommodate the new tunnel, as well as the boot. In between all of this, Alby was busy plating and polishing a host of parts, while Mark Sant from Ontrak Auto Electrical weaved his magic to put together a sanitary new electrical harness – all in record time!

The amount of grunt on tap, combined with the aggressiveness with which it kicks in, make the over-hook good insurance – having your foot slip off the loud pedal could be disastrous

“It drives unbelievably good, way better than most of the cars I’ve driven,” says Brett. “Especially considering how wild it is and the fact it’s only had a hurried tape-measure alignment. I’m afraid to get a proper wheel alignment in case it ruins it!

“It was such a massive push to get it done in such a short period,” he continues. “I drove it for the first time two days before the ’Nats.Luckily for me the ProFlo boys loved working on the car and got it done for me, and nothing has gone wrong! It’s turned out way better than I’d hoped – I can’t thank them enough.”

That’s a lot of hoses! There are two fuel lines (feed and return), two power steering hoses and two transmission cooler lines

This HT Monaro is destined to go down in history as one of the toughest cars ever built in this country – almost like Wayne Pagel’s GAS69 reborn with a modern twist. An instant classic, that’s for sure!


BRETT Hewerdine and Simon Rasic had been very close friends for many years. A few years after Simon’s passing in 2014, the family was looking to sell his collection of bikes and cars, including the Monaro.

Brett had Simon’s initials engraved into the butterflies, as well as the crown in the middle, which matches Simon’s neck tattoo

“Simon had been building it for a lot of years and I didn’t want it to disappear,” Brett says. “I made the decision to do the right thing: buy the car and finish it the way I know Simon would have wanted – as a tribute. Having built several bikes for him, I know what Simon liked. I’m pretty sure he would be happy with how the car turned out – right down to the number plate.

“I’m missing him every day, and that’s why the Monaro will always be there; it’s not going anywhere – Simon’s family are always welcome to use it.”


Paint: Spies Hecker Black

Brand: 510ci Donovan
Hat: Big & Ugly
Blower: Littlefield 14/71
Inlet manifold: ProFlo- fabricated
Heads: Big Chief
Pistons: JE
Crank/Conrods: LA Enterprises Kryptonite
Ignition: Bosch Electronic
Fuel system: ProFlo EFI with eight 2000cc injectors
ECU: Haltech Elite 2000
Oiling: Dry sump
Radiator: Shaun’s Custom Alloy
Preferred fuel: E85

Gearbox: Full-manual TH400
Diff: Strange alloy, 35-spline
Third member: 3.55:1 Detroit Truetrac
Tailshaft: ProFlo

Front: Rod Shop IFS shortened
Front: Viking coil-overs
Rear: ProFlo four-link, Strange coil-overs
Brakes: Wilwood; six-piston (f), four-piston (r)
Master cylinder: Wilwood

Rims: Weld Racing;17×4.5 (f), 15×14 (r)
Rubber: M&H P185/55R17 (f), M/T Sportsman Pro 31×18.5-15LT (r)

Paul Sant and the ProFlo Performance crew; Mark Sant (Ontrak Auto Electrical); Adam (Just Engine Management); Anthony Caronna (Anthony Caronna Custom Bodyworks); Shaun (Shaun’s Custom Alloy); Darren (Stitched Up Custom Trim); Alby (plating and polishing)