Description:

21-tooth, red. Note: If your speedometer read to high, a drive gear with one more tooth will slow it down approximately 5 MPH Size: N/A Corvette Central #: 531507 Original GM #: 3987921 Car years: 1961, 1962, 1963, 1964, 1965, 1966, 1967, 1968, 1969, 1970, 1971, 1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981.