Maximum Effort Ford 289-351W 3/8-24 Rocker Arm Stud Girdles Designed to increase the strength and rigidity of the rocker arm studs by eliminating flex and thereby assuring true rocker arm ratios. Howards stud girdles are made from the highest quality aluminum. They are springloaded for easy removal and are anodized purple. A must for all competition engines not using shaft rockers. Locking hex head adjusters are included. Made in the USA.