I'm in the process of building a scavenger kit for my 89lx. Gonna come from both valve covers, into a y, to a catch can, then to the exhaust. From both valve covers to the y than catch can would -4 an work? Than was gonna run -6an from the can to the exhaust. Also gonna install a check valve between can and exhaust. Tired of smelling the gases. The venturi going into the exhaust should pull 3 to 4 lbs of vacuum. Thanks for any advice.