I 'm looking for tuned pipe for a recently acquired YS. 61 LS rear exhaust engine. I see Hatori lists the good old 650( that I used with my YS .60FR ). Then there is the newer Hatori 700 pip which is longer. Which would work better with the .61 Long Stroke engine? I'm planning on ordering from these folks. http://www.tokyo-hobbies.com/hatori.html Anybody ever do business with them?