1969 GMC K15/K1500 Suburban Engine: 6.5L V8; Standard Rotation|Standard Duty Thermal Fan Clutch;. 1968 GMC K15/K1500 Suburban Engine: 6.5L V8; Standard Rotation|Standard Duty Thermal Fan Clutch;. 1972 GMC K15/K1500 Suburban Engine: 6.6L V8; Standard Rotation|Standard Duty Thermal Fan Clutch;.