I have a 200 SHO on an Xpress 20 ft. I know someone who has the 200 4 stroke yamaha non sho. They could not put it on my boat 4 yrs ago when I bought mine. Shaft was to long then is the excuse the dealer used. His is 1 year old and also a 20 ft Xpress. He told me top end by himself is 56mph. Top end by myself with the SHO is 65. But the SHO does cost more. Check with Bill at BRM Marine, he can help you. Arkansas board.