MSD DISTRIBUTOR GEAR, BRONZE -- Fits Pontiac V-8; 0.5 in ID; Includes roll pin; Machined from quality AMPCO 45 aluminum bronze containing 5 percent nickel creates high-strength gear teeth that are less prone to wear even with high-volume oil pumps; For aftermarket distributors with 0.5 in. diameter shaft; Does not require drilling; Not intended for extended street use.