1968 Chevrolet K20 Pickup Engine: 6.5L V8; Standard Rotation; Standard Duty Thermal Fan Clutch;. 1969 Chevrolet K20 Pickup Engine: 6.5L V8; Standard Rotation; Standard Duty Thermal Fan Clutch;. 1970 Chevrolet K20 Pickup Engine: 6.6L V8; Standard Rotation; Standard Duty Thermal Fan Clutch;.