I'm in the process of converting my boat over form thru transom exhaust to OT wet headers. I have the headers, steel lines an tee and so far. I know that I need a 3/4" water dump and a gate valve for that same dump. What else do I need? I've seen members in the past talk about pressure relief valves and a gate valve located near the driver seat. Do I need these 2 items as well. Also, the exhaust that I took off was wet logs and the front of each log had 2 water supply lines. What do I to with the 2 extra lines I will have left over? Also, I found a picture that a member posted of the water pipe coming off his jet. Looks like he spliced into it and added an additional valve. Is this to have sepearte control of the engine cooling and header water?