1975 GMC C25 Suburban Engine: 4.8L L6; Standard Rotation; Standard Duty Thermal Fan Clutch;. 1975 GMC C25 Suburban Engine: 5.7L V8; Standard Rotation; Optional Standard Duty Thermal Fan Clutch;. 1976 GMC C25 Suburban Engine: 4.8L L6; Standard Rotation; Standard Duty Thermal Fan Clutch;.
