Valve sizes: 1.94/1.50-inch intake/exhaust, 11/32-inch stem

Intake runner: 170 cc

Chamber: 64 cc

Valvesprings: Single wire w/damper 1.235-inch od, 0.875-inch id 75-pound seat pressure @ 1.700-inch installed height Coil-bind @ 1.150 inches

Valvespring seat: 1.300-inch od, 0.850-inch id

Valve-guide seals: Viton rubber positive seals Total 0.450-inch retainer-to-seal clearance

Max valve lift: 0.420-inch (allows 0.030-inch retainer-to-seal)

Rocker stud: Press-in, 3/8-inch diameter No guideplates

Intake bolt pattern: Four bolts per side

Spark-plug style: 14 mm, ¾-inch reach, tapered seat

Spark plug: AC R44TS, AC R44LTS, AC Rapid Fire #8 RS12YC Champion, Autolite 104 or 26, ACCEL 516, Bosch HR10B or HR10BX, HR9DC

Rocker arm: Guided style necessary

Valve cover: Center-bolt style