1987 GMC R2500 Suburban Engine: 6.2L V8; Standard Rotation; Severe Duty Thermal Fan Clutch; Fan Mounting Holes are 5/16 In.;. 1988 GMC R2500 Suburban Engine: 6.2L V8; Standard Rotation; Severe Duty Thermal Fan Clutch; Fan Mounting Holes are 5/16 In.;.