All Vortech V3 superchargers are shipped with temporary vent plugs in the ventilated gear case assembly. These are permanent replacement plugs to install after removing the shipping fittings. Without the proper vented plugs in place, you will blow the seals out of your supercharger. A ventilated gear case assembly eliminates any potential internal pressure issues that are currently associated with non-vented competitive designs. Vortech parts will keep your supercharger at optimum performance levels.