Although NASCAR sponsored several compact-car races through 1961, the two held in conjunction with the '60 Daytona 500 clearly demonstrated the effectiveness of the factory-hopped-up 170 Slant Six. The first was a 10-lap race over a 3.81-mile road course in which Valiants took the top seven spots, with Marvin Panch leading the way with an average speed of 88.134 mph. The second race, a 50-mile charge around the 211/42-mile Daytona tri-oval, opened some eyes. Again, Valiants dominated the top positions, with Panch's Valiant again claiming the victory with an astonishing 123.282-mph average speed. Panch got $1,900 for each win (a total of $3,800 for the day), and the legend of the Slant Six-powered Daytona Valiants was born.
In 1961, many (but not all) of the parts designed for the '60 Daytona Valiants were made available to the general public as a dealer/owner-installed kit for any 170 or 225. Dubbed the Hyper-Pak, it cost $403.30 and carried PN 2205573. Included was a hotter mechanical cam and lifter set (276/268 duration, 0.430 lift); stiffer pushrods; Carter 2951-S AFB four-barrel carburetor; low-profile air cleaner; two-piece cast-iron exhaust headers; high-flow single exhaust with bolt-on chrome tip; revised accelerator linkage; high-capacity clutch and pressure plate; and one of the wildest intake manifolds ever produced by Detroit.
By hanging the carburetor 2 feet away from the cylinder head, the streamlined 15-17-inch-long runners allowed Chrysler engineers (many of whom were members of the Ram Chargers during off hours) to take advantage of the pressure waves that pulse back and forth between the intake valves and carburetor, providing a slight resonant tuning effect at about 4,500 rpm. In essence, when the intake valves open, the incoming fuel air charge enters at a slightly faster rate than that created solely by the falling piston during the intake stroke. The result of this mild form of free supercharging is increased charge density and added power. Chrysler rated the 170 Hyper-Pak at 148 hp (as apposed to 101 hp in stock form) and the 225 Hyper-Pak at 196 hp over 145 stock.
The Hyper-Pak kit was discontinued in 1963 after a few hundred were produced. At over four bills, it cost nearly one quarter the price of a stripped Valiant or Lancer. But Chrysler wasn't concerned with volume; all it needed was for NASCAR to acknowledge the Hyper-Pak as a factory option so it would be legal for racing. Today, the legacy of the factory Hyper-Pak kit lives on in Clifford's repop intake manifold. Then, as now, it never fails to blow minds whenever the hood is lifted.