1989 Chevrolet R3500 Engine: 5.7L V8; Reverse Rotation; Optional Standard Duty Thermal Fan Clutch; Fan Mounting Holes are 10 mm.;. 1990 Chevrolet R3500 Engine: 5.7L V8; Reverse Rotation; Optional Standard Duty Thermal Fan Clutch; Fan Mounting Holes are 10 mm.;.
