549hp 1971 Ford XY Falcon 500 sleeper

Mark Whelan has been wanting a wolf in sheep’s clothing since before it became fashionable

Photographers: Troy Barker

MARK Whelan is proud to trumpet the aural credentials of the stout 549hp, 521lb-ft Clevo under the bonnet of his sleeper XY Falcon: “It’s loud and obnoxious!”

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

Mark had always desired Ford’s factory-option wind-back sunroof. “It took ages to find a good, working sunroof, but I ended up getting an entire roof about seven years ago,” he says. Mark then enlisted All Car Restorations to unpick the XY’s roof skin to swap it out with the donor. “They then welded it back in and lead-filled the C-pillar join. There’s no cuts, so all of the chrome fits perfectly. It’s just awesome to wind back the sunroof and cruise around”

He didn’t forget to swap out those skinny 14-inch steelies for steamrollers, though. Nope, Mark’s been wanting a wolf in sheep’s clothing since before it became fashionable. “I always liked the sleeper thing,” he says. “I find that everyone is doing the GT lookalike, and I do like that, but I’m an old-school dude; it is what it is.

Mark does swap out the meek 14×6 factory steelies for a set of Center Lines when he feels the need to give the XY some jandal. “Most people like the standard look, and as it’s so loud, the hubcapped grandpa look is good,” he says

“I bought the XY about nine years ago, as I’d always wanted one,” Mark continues. “I had an XA GT when I was 21 years old and I sold it when we got married and had kids.” So, with the kids now grown, it was time for Mark to get back on the horse. He garnered himself a tight example locally, sporting a 351ci Windsor, C4 and nine-inch. “I searched for two years to find an XY with a good, original body that hadn’t been painted or bogged,” he says. “There was a small ding in the left-hand guard that’s been repaired and two 50-cent sized rust bubbles in the front door bottoms, but that was it. Starting with a fairly virgin body ultimately saved me from spending a shitload of money on bodywork.”

“I had a copper pull me over as I was cruising along,” Mark says. “He asked if it was my car. I said: ‘Absolutely,’ and he responded with: ‘That’s mad!’ He just started taking photos and got me to pop the bonnet. He absolutely loved it”

Another tick was the fact that the driveline was already packed with hefty factory niceties. Even so, a stock 351-cuber was never going to be enough for Mark. “I bought another 351ci that someone had built up, but the head cracked 12 months in,” he explains. “So I decided to buy brand new and get an Arrow Cleveland block, alloy heads and forged internals.”

The 408ci set-up is fed by a Holley 750 HP carb through a Weiand X-CELerator manifold. CHI heads packed with a Crower solid flat-tappet cam are matched with SRP forged slugs, making for a decent 11.0:1 compression on pump fuel. Scat crank and rods round out the stroker, lubed by a Melling oil pump via a nine-litre sump. Mark also upgraded the diff to a GT LSD and got cracking on a few extra tweaks, seeing the upgrade draw out to a two-and-a-half-year build.

“The original paint was showing wear and tear, so the XY was repainted – after the factory sunroof went on,” Mark says. And boy, that was a job and a half, from locating a decent example to unpicking the entire roof to fit the factory option through to lead-filling the completed job. “Cutting through the pillars is the cheap and easy way, but then nothing lines up, so it’s a shit way of doing it,” Mark says.

Mark’s mate Damo ‘Wade’ Garrett laid down the Nugget Gold paint paired with an Ultra White roof, keeping the car’s subtle stocky vibe. The brown 70s goodness continues inside, aside from a couple of monitoring essentials that have been neatly tucked away.

“I added a B&M Pro Rachet shifter, GS dash and GS steering wheel, but I didn’t want to go too far from original,” Mark says. “Tucked below the dash are three Auto Meter gauges, as the factory ones aren’t accurate. I slid in an Auto Meter tacho where the original one is meant to go, so other than the shift light on the steering column, it all looks pretty original”

“I love that it’s a sleeper,” Mark grins. “People hear it well before they see it, and the looks on their faces when they spot a grandpa-spec car sounding like it does is gold!

“My wife Maree loves the car as much as I do,” he continues. “She had Damo paint up the old retro Esky to match the car, and we use it on day trips.

“When The Bend Motorsport Park finishes its drag strip, I will take it for a few passes to see how it goes. I’d think it’d run in the 11-second quarter-mile range as it has a 4000rpm stall and the right diff gears, but who knows. It makes tons of steam – plenty for the street. So I’m pretty happy with where it’s at right now.”


Paint: Nugget Gold with Ultra White roof

Brand: Arrow Cleveland 408ci
Induction: Weiand X-CELerator manifold, Holley 750 HP carb
Cam: Crower solid flat-tappet
Heads: CHI
Crank: Scat
Conrods: Scat
Pistons: SRP forged

Trans: C4 full-manual
Converter: Dominator 4000rpm
Diff: 9in, GT Detroit Locker, 3.9:1 gears, 31-spline axles

Springs: Stock (f), lowered 2in (r)
Shocks: Stock (f & r)
Brakes: XY discs (f), GT 2½in drums (r)

Wheels: Ford 14×6 steelies (f & r)
Tyres: 195/75/14 (f & r)

Damo ‘Wade’ Garrett for the strip-down, paint, panel and reassembly; Sam at SA Race Transmissions & Differentials for building me a killer trans and setting up the diff; Romano at All Car Restorations for a perfect job fitting the sunroof; Serge at Winner Products for the rooflining; John Skorpos at JSR for a trick dyno tune and setting up the new engine; Pat Farrugia for his patience and guidance

Got a car that looks mild, but goes wild? Send pics, car details and contact details to: Sleepers, Street Machine, Locked Bag 12, Oakleigh, Vic 3166. Or email: [email protected].