I am getting ready to put a new transom plate on my boat. But I have one question. Should I use any sort of sealer on it along with rubber gasket? I bought a new rubber gasket that goes around the transom plate and I also got new gaskets for the bolts. Also where can I find a block off plate for where fresh water comes through the transom plate? I put a external raw water pickup on the boat because I was having problems getting fresh water through the drive. thanks