We followed up the rocker swap with an Edelbrock Performer dual-plane aluminum intake. $120
The '70 Chevelle now fitted with the Lunati rocker arms. Power measured at the rear wheels.
The Performer intake flows more air than the portly factory iron piece. Equally important is that its more modern design evens out the airflow between cylinders. Both factors lead to a nice increase in power.
Roller Rocker Arms
Lunati Voodoo 1.6:1 roller rocker arms. $338
A bone-stock '70 Chevelle SS convertible powered by an RPO L65, 9.0:1-compression 350 small-block, which came factory rated at 250 gross horsepower and 345 lb-ft of torque, running through a Turbo 350 trans. The only modification was a 21/2-inch dual exhaust system with turbo mufflers. Power measured at the rear wheels.
Some of the increase undoubtedly came from the extra lift provided by the rocker arms, but Lunati's James Humphrey told us most of the gain likely came from the decrease in valvetrain friction achieved by installing full roller rockers in place of the factory stamped-steel pieces.