1988 GMC C1500 Engine: 4.3L V6; Reverse Rotation|Standard Duty Thermal Fan Clutch|w/ 3.42 Or Lower Rear Axle Ratio; Fan Mounting Holes are 10mm. 1988 GMC C1500 Engine: 5.0L V8; Reverse Rotation|Standard Duty Thermal Fan Clutch|w/ 3.42 Or Lower Rear Axle Ratio; Fan Mounting Holes are 10mm.
