I have an HDS8 with the 2.25″ ball and short 5″ arm. The square base is bolted down 2″ from the left edge of the raised mounting area. I have a round hole and cover plate under the trolling motor pedal for access to the nuts. I also have one of those rubber blocks that supports the arm when in the down position. Cougar FTD. I have 5″ clearance to the TM pedal on the left, on the right it overhangs the raised part of the deck 2.5″. With the plate level it wont hit anything. Eyeballing it, I dont see a problem mounting a 12. See my profile for a couple of pictures.
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