A Corbin Road King
Seat will not fit any of the glides (Road Glide, Street Glide, Ultra Glide).
The differance is the console, Corbin seats come over the back edge of the tank and wrap over the console. The glide consoles (Gas fill in the console) come back at a taper. The Road King console come back stright and square.
All the Glides will interchange (Within the correct year model) but the Road King is it's own animal.
A Glide will have FL in the seat part number. A Road King will RK in the part number.
Also, the passenger pillion (Back Seat) are all the same all will have FL in the part number.