Wilwood 140-16910 Wilwood 55-57 Chevy Bel Air Aerolite 6R Kit, 5 x 4.50in/4.75in Hub - 14.00in Slotted RotorWilwood 140 16910 Wilwood 55 57 Chevy Bel Air Aerolite 6R Kit, 5 x 4. 50in 4. 75in Hub 14. 00in Slotted Rotor AERO6 calipers are the newest design for the specific purpose of providing big capacity braking with large diameter rotors for heavy weight and extreme duty vehicles. For cars, its the biggest of the big providing big brake performance for show and dual purpose street and track vehicles. For trucks and SUVs, it provides big stopping power for