I have a 91 Thompson with twin 4.3 Alpha 1's, I am looking at installing a Simrad AP12 autopilot, but will have to change my rack/pinion steering system to a rotary set up. My concern is with the cable steering and only the starboard having power steering, I am afraid the unit will really have to work when I am trolling on the port engine, my question is , can power steering be added to the port eng. ? What will have to be done for check valves etc.. maybe this isn't even possible, I guess maybe thats why it didn't come from the factory. Would I be better off to add a Sea Star hydraulic system ?