These Scorpion Racing Products SCP1014 BBC Roller Rocker Arms feature a 1.7 Ratio and fit 7/16 Studs. These Race Series rocker arms are designed for 396-502 inch Big Block Chevy engines, and are CNC machined from 7000 Series Aerospace-Grade aluminum for maximum strength and durability! Scorpion SCP1014 Race Series BBC Roller Rocker Arms Feature: For 396-502 cubic inch Big Block Chevy Mark IV, Gen V, Gen VI and 8.1 Vortec engines Rockers for cylinders #1 and #8 are machined for valve cover clearance Will handle .950” lift & 950 lbs. max open spring pressure Clear 1.625” valve springs 1.6” fulcrum width Full body design Needle Bearing Fulcrum and Roller Tip Centerless Ground Trunnion, Pin & Roller Blue Anodized for additional protection and durability Burr-Free Thru Hole in Trunnion Large Machined Seat Thick-Walled Adjusting Nut Pedestals Machined from Solid Steel Black Oxide Coated Steel Parts Set of 16 Lifetime Warranty 100% Made in the USA! Made for the most demanding street and racing applications, Scorpion’s top quality Race Series Roller Rocker Arms provide superior performance and more horsepower!