ARP Rocker Arm Nut - 7/16-20 in Thread - 0.600 in Shank Diameter - 1.200 in Long - Chromoly - Black Oxide - Aluminum Rockers - Set of 16 Micro Sprint Seat GP-1 Break-In 30 doesn’t require

GP-1 Break-In 30 doesn’t require any additional ZDDP or break-in additives

Fully assembled or bare heads can be ordered with combustion chambers matched to your bore size

A slide collar opens up quick flow ports for fast air dumping to purge tires in record time

1965-1981 Oldsmobile Cutlass

ARP Rocker Arm Nut - 7/16-20 in Thread - 0.600 in Shank Diameter - 1.200 in Long - Chromoly - Black Oxide - Aluminum Rockers - Set of 16 Micro Sprint Seat GP-1 Break-In 30 doesn’t requireA rocker arm adjuster that doesn't require special tools and won't work loose. Threads on the heat treated Perma Loc Adjusters are machined exactly perpendicular to the adjuster bottom. a set screw is also machined flush on the bottom. All of these features help eliminate setting valve lash on a regular basis. Since 1968, ARP is the fastener of champions and the world leader in fastener technology. Product Description: Rocker Arm Nut 7 16 20 in Thread