pearson 26 autopilot
The Pearson 26 has an ''S'' shaped tiller that emerges from a short rudder tube (maybe 3-4 inches above the cockpit sole) and curves up and then horizontal again. As I understand this, the problem is that the autopilot needs to install on the part that curves up and which is below the height of the seat. What I gather is that the piston is too long to fit into the footwell without hitting the side of the cockpit.
The answer, of course, is to install an offset bracket on the side of the tiller that extends toward the opposite side of the cockpit from the side where the tiller pilot is mounted. Its not too hard to build an offset bracket in a sturdy wood like white oak or to laminate one or get one welded up in aluminum.