Removing old transducer fairing block or leave it on?

[Sketchywind]

I upgraded a 2001 Grady 265 with a Simrad evo2 from a Northstar GPS and Sitex MK 2 106 sounder. The existing transducer fairing block is between two seacocks in the aft bilge. It doesn't read well over 10 knots, so the seacocks may be too close to the old transducer. I'm planning on installing a 20degree B150m transducer just forward of the port seacock and a transom mount down scan skimmer.
Is it necessary to remove the old fairing block or can I leave it on? It has a 3/4" hole and 2" paddle wheel hole.
Is there an alternative flush mount location on a 265?
Thanks!