You have to have a wastegate flange welded to your manifold before the turbo to use an external gate. I don't know how you would run an external gate off that little ass wastegate port on the exhaust housing. Thats whats causing the over boost to start with, the port isn't big enough to rid the all of the excess exhaust. As far as covering the existing port, buy a new exhaust flange for your turbo, they make them so it blocks that hole off.