Flow-Rite System 2 is the valve that does auto and empty. So your new plumbing set up will be a little different than factory anyways depending on year model. Factory you likely had an open/closed valve only that was in line with the overflow and bottom livewell drain that came out of the hull...
Allison offers a machined derlin block that bolts to the bottom of the skid planner and the the transducer bolts to it. Keeps the ridges of the planer from interfering with the side scan beams.
What boat were you running this on? I have a XB2003 w/225 pro max. Wondering if the modifications you made will help or hurt. My intentions would be to use it as a fishing prop.