575-cube big-block Ford engine – Mill of the Month

Ultim8 Car Fit in Albury built this tough engine combo for Damian Allitt's XC streeter

Photographers: Luke Hunter

An XC Falcon sedan isn’t a small car, so if you want to run eights in one you’re going to need plenty of grunt. Mark Connors, owner and engine builder at Ultim8 Car Fit in Albury, knew exactly what the answer was when customer Damian Allitt asked for a tough engine combo for his XC streeter: cubic inches.

This article was first published in the January 2020 issue of Street Machine

“When Damian first came to us, he had very specific requirements for power, and we weren’t sure a factory block would handle that in a street car,” Mark explains. “Initially he was hoping for around 800hp, but he ended up wanting to push 1000hp and add nitrous, so we rang John Kaase in the USA.”

This big-inch powerhouse is based around an aftermarket Ford Motorsport block with a 4.5in bore, stuffed with an Eagle forged crank, custom 13.5:1 Diamond pistons, Scat rods and a custom solid-roller cam running 290 degrees duration at .050in lift. Up top is a set of SR-71 Kaase heads – the highest-flowing big-block Ford head with conventional port locations – topped by a Kaase intake manifold.

“When I first saw the specs I was blown away, but Kaase assured me it would make power by 6500-7200rpm,” Mark says. “We could theoretically rev it to 8000rpm, but Damian doesn’t want to be setting valve lash every weekend or beating on the valve springs.”

Damian will also have up to 400hp of nitrous up his sleeve just in case he gets bored. “We have a controller to allow us to bring it in gradually in stages,” Mark says. “Traction could be a problem for him, so the adjustability is needed.”

An ICE ignition system handles the electrons, while a single four-barrel Quick Fuel 1250 Dominator carby has been set up for E85 thanks to the BBF’s high compression and power goals. “When you’re getting north of 800hp, it’s hard to do it on pump fuel, and E85 gives a better window for tuning,” Mark explains.

Sitting on the bottom of the fat-block is a custom sump made by Melbourne engine legend George Haddad.

“The sump is a work of art,” Mark says. “We had George build us a sump with gates and trays. We fitted the engine on a Tuff Mounts kit and fitted an RRS strut-tower notch kit, so there won’t be any problems getting a big set of pipes in there. We’re looking into making custom pipes for it now, most likely 2.25in that will potentially step up to 2.5in.

“It is ridiculous how big it is compared to a Cleveland,” Mark continues. “It is probably one-and-a-half Clevelands in weight. My heaviest engine stand is right at the limit for this engine!”


“This is the third big-block Ford we’ve done, and you just don’t see many in Australia,” Mark says of the 575ci brute he built for Damian’s XC. He says Damian is hoping for an 8sec pass out of the untubbed, ’caged sedan, but he is realistic that it might be a tough ask on stock leaf springs and a 275 radial. “There are definitely limitations with it still being a street car,” Mark laughs.