Hey ptgarcia, I am not familiar with the HS 65 servo, however the only mod needed for the HS 56 was to cut off the vertical mounts and the mounting on the underside of the servo. Also to make life easy, align and pre drill the holes you need to accommodate for how you are going to mount it before you put the frame together. It is a pain to do it after the frame is assembled. I cut up and sanded an old control horn to achieve the correct spacing for the aileron and elevator servos in the frame. I went with the HS 56's because there was no slop at all; the servo was tight and has been a great performer so far.