1987 GMC G2500 Engine: 4.3L V6; Reverse Rotation; Optional Standard Duty Thermal Fan Clutch;. 1987 GMC G2500 Engine: 5.0L V8; Reverse Rotation; Optional Standard Duty Thermal Fan Clutch;. 1987 GMC G2500 Engine: 5.7L V8; Reverse Rotation; Optional Standard Duty Thermal Fan Clutch; Fan Mounting Holes are 10 mm.;.
