427-cube Cleveland – Mill of the Month

Tony De Marco's 427ci Cleveland donk is destined for his freshly restored, Howard Astill-build XC Cobra

Photographers: Will Horner

WHEN the owner of this magnificent mill, Tony De Marco, told legendary car builder Howard Astill that he wanted a brand new Cleveland donk for his XC Falcon Cobra build, Howard just about told him to get stuffed: “You can’t buy a new Cleveland; you haven’t been able to do that for bloody years!”

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

Fortunately, a compromise was found with A-list engine builder Sam Fenech from Westend Performance, who knocked out a 575hp street package for Tony that would make any Ford fan drool.

Sam started off with the best, ordering up a brand new Arrow Cleveland block from Perth as the base for the build. Tony specifically requested a street-friendly package that ran on humble pump 98, could be used every day and was built with all-new components. With those instructions, Sam set about building a stout 427ci package with a Scat crank, Scat H-beam rods and SRP pistons. Oiling is taken care of with a big Moroso pan, oil pump and pick-up kit. The cam is a hydraulic-roller built to custom specs in the vicinity of 240 degrees, with Comp Cams lifters and all the other fruit to make it sing to 6200rpm.

To keep the engine happy on PULP 98, the compression was set at a modest 10.7:1, while the top end consists of CHI 208 heads and a trick CHI dual-plane manifold, which helped Sam reach the power and torque figures he was after. “I’ve done a bunch of engines like this before, and I knew with the stroke what sort of horsepower we would end up with,” he says. “I was more interested in pushing the torque figures up, and getting that smooth driveability that would be needed for a car with a manual ’box.”

The whole lot is controlled by a Holley Sniper EFI kit, a self-learning deal that makes initial set-up a breeze and gives the mill day-to-day driveability. All up, the package made a nice and linear 575hp and 575 ft-lb on the engine dyno at Westend.

Howard has had the engine patiently waiting for its new home since late last year, and at the time of writing he plans on dropping it into the freshly restored Cobra in the next few weeks. Backing up the donk will be a five-speed Tremec TKO600 ’box, ensuring owner Tony will be able to fully enjoy all 575 of those ponies with a mere breath on the throttle.

“I just wanted to build a car with the old-school style but with a modern feel,” Tony says. “I trusted Howard to do that for me and he’s delivering on that really well.”

Cleveland mill

Brand new old-school: Tony’s XC Falcon Cobra coupe

HOWARD Astill has been building bad-arse cars for years now, and the genuine XC Falcon Cobra coupe that this mill is destined for is no exception. Build #66 from the factory, the car came with the larger 351 Clevo compared to the 302 of later builds, but the original engine and four-speed manual were long gone when it rolled into Howard’s shop.

It has been given the full rotisserie treatment while being updated with a modern feel, with not a nut or bolt spared in the process.