1970 Chevrolet C30 Pickup 4.1L L6. 1970-1974 Chevrolet C30 Pickup 4.8L L6. 1972-1974 Chevrolet C30 Pickup 4.1L L6. 1973-1974 Chevrolet C30 Pickup 4.8L L6. GENUINE NGK SPARK PLUGS . Plugs feature a fine-wire Iridium center electrode and Nickel-alloy ground electrodes for maximum engine horsepower and torque.