1967 GMC P25/P2500 Van Engine: 4.1L L6; Standard Rotation; Optional Non-Thermal Fan Clutch;. 1967 GMC P25/P2500 Van Engine: 4.6L V8; Standard Rotation; Optional Non-Thermal Fan Clutch;. 1968 GMC P25/P2500 Van Engine: 5.0L V8; Standard Rotation; Optional Non-Thermal Fan Clutch;.
