enny Steward / Port Orange, FL
When Chrysler unleashed the Hemi on the world in 1964, any car dressed in aluminum would have required the legendary cross-ram intake to be legal in NHRA Super Stock racing. There was fuel injection back then, in the form of mechanical Hilborn stacks, as well as wheelbase relocating that resulted in the earliest ‘funny cars’ the following spring. Thanks to foresight by Mopar when releasing the current Drag Pak race cars, the crate motor used in these modern cars can now be placed into a GT-class Super Stocker. Denny Steward, a long time Mopar racer and owner of Steward Performance Products, showed up at the NHRA U.S. Nationals with Carl Weisinger’s big 1964 Plymouth, a beast whose newly-lightened front end (the big A864 1964 Hemi package even had steel heads on it) found daylight on every pass. Here’s how it is done.
The program began with a 2009 Drag Pak 5.9-liter engine, which is actually considered a ‘milder version’ than the more recent iterations. The iron Mopar R block features a 4.060 bore and mild (0.013-inch increase) stroke on the Eagle crank for a true displacement of 372-ci. The bottom end uses Diamond Pistons, Total Seal rings, and Carillo I-beam rods. A specially fabricated aluminum pan adapts the 21st Century oil system to a 1964-era K-member layout, and the whole thing was put together by Denny in his Port Orange, Florida engine and parts business Steward Performance. The dyno sheet showed an eventual number of 690 hp.
Heads and Valvetrain
The cam is a real power pack with duration specs of 272/277 degrees duration,, and lift numbers close to 426 Hemi status at 0.816-inch on the intake and 0.736 exhaust. A Jesel belt drive keeps it in synch, with Jesel rockers, Manley valves and springs, and Steward Performance pushrods under the custom valve covers. The factory Mopar heads were treated to SS-legal changes thanks to Competition Induction Service.
Com-Fab gets the credit for the pipes, which are a custom tri-Y design created for this car.
Intake and Ignition
Nothing makes folks scratch their heads like a distributor with no wires on it. The MSD front-mounted example provides more accurate crank-triggered timing than the rear-mounted distributor would. Though it no longer doles out the spark energy, the old distributor remains in place to drive the oil pump. The engine breathes in through Edelbrock’s Super Victor high-rise single-plane manifold. The injection unit on top of that is the OEM Drag Pak version, and tuning is done via Big Stuff 3 coupled to an MSD 7AL-3 discharge box.
Like the original Hemi, the rest is basics, with a Mezeire water pump, Red Horse braided lines and fittings, positive crankcase evacuation through the valve covers, and that beautiful billet throttle return (which you can buy) came from Denny’s own milling equipment at Steward Performance as well.