Billet Wheel Spacer - Wide 5. Billet Wheel Spacers are manufactured from 6061T6 Aluminum and are 3/8" thick. They can be used for obtaining a wider track or needed clearance for Brake Calipers and Tire to Spring Plate Clearance.Billet Wheel Spacers are sold individually. Please check that your wheel mounting studs are long enough before operating the vehicle. A full nut of wheel stud should be considered minimum.