Assuming that your Coachmen Encore has an F-53 chassis the correct steering stabilizer for a Class A with a V8 engine would be the Roadmaster Exact Center Steering Stabilizer # RM63RR if your GVWR is under 22,000lbs or the # RM82RR if it's over 22,000lbs.
If you could give me the model number of your Encore I could narrow it down to the exact kit for you. As for the difference, the RSSA is discontinued and and being replaced with the Exact Center, which utilizes steel rods/pistons and... view full answer...