1968 Chevrolet P10 Van Engine: 3.8L L6; Standard Rotation; Standard Duty Thermal Fan Clutch;. 1968 Chevrolet P10 Van Engine: 4.1L L6; Standard Rotation; Standard Duty Thermal Fan Clutch; w/ A/C;. 1969 Chevrolet P10 Van Engine: 3.8L L6; Standard Rotation; Standard Duty Thermal Fan Clutch;.