The Polito name has long been associated with the aspirated, high-rpm world of Aussie Pro Stock racing, so this blown big-block Ford doesn’t seem like the family’s usual fare. We asked Tony Polito to give us the skinny on this mountain of a motor.

First published in the April 2025 issue of Street Machine

“We’re building this for a customer who would like to put it into a ’39 Zephyr, like Benny Gatt’s,” Tony says. “He’s not afraid to spend money on good parts, so it has good stuff all through it.”

Zephyrs are legendary in the custom and hot rodding world, but it’s relatively rare to see them built into bona fide street machines. This one, however, will be getting all the right hardware to turn it into a nickel-tough example, and it all starts with this engine.

“It’s a Ford Motorsport block with a Bryant crank, Carrillo rods and JE pistons, so it will be 632 cubes and sit at around 8:1 comp,” says Tony. “With 632ci, it’s going to make a heap of power anyway, and he doesn’t need much in an old car like a Zephyr. It’s going to make way more than 600hp, and that’s probably a bit too much in a car like that!”

The Polito crew specced out the valvetrain with a solid-roller Comp cam and matching lifters, working Manton pushrods and Jesel rockers.

Sealing the cylinders are drool-worthy Kaase Boss Nine heads, which are based on Ford’s legendary Boss 429 hemi heads but engineered for better reliability and a more stable power-making platform. Kaase added material to the deck to prevent cracks forming in the combustion chambers – a common problem with the original Boss heads. The rocker arm mounting locations have been simplified as well, allowing for the use of cheaper, more commonly available rocker assemblies than the originals, and the exhaust rockers have been extended to move the pushrods away from the deck, improving geometry.

A hefty Blower Shop 6/71 air pump mounted on a Swartz Racing Manifolds plenum crowns the whole affair, drinking through a pair of Quick Fuel four-barrel carburettors. Spark is sent out from a Swartz Racing offset billet distributor with an MSD cap, while the fuel and oil systems will be plumbed with Speedflow fittings and lines.

With so much sauce above the crank tunnel, the Polito crew knew that keeping oil up to the big-block would be critical. To that end, a slimline alloy oil pan from Stef’s Fabrication Specialties will be plumbed to an LAT billet oil filter and a four-stage dry sump set-up.

In addition to the big blower snout, the front of the engine is crammed with street car features like power steering and air conditioning, running on a Billet Specialties front-drive assembly. “The customer intends to drive this car, so he wants all the creature comforts,” Tony explains.

“To fit such a big engine in a small, narrow car like a ’39 Zephyr, they’ve had to widen the car five inches and lengthen it as well,” he continues. “It will have a C6 behind it with a Gear Vendors overdrive unit, so it should be a really nice thing once it’s done.”

OBSTACLE COURSE

The front-mounted distributor on fat-block Fords creates a few clearance issues for belt paths and ancillaries on big-horsepower set-ups like this 632. The Blower Shop 6/71 pump needed an offset snout to get past the dizzy, which itself uses a heavy offset set-up from Swartz Racing to push the MSD cap away from the pulley snout.

Polito’s Automotive Services
Wetherill Park, NSW