These tuff as nails raw steel struts mount on the inside face of your Shovelhead frame and follow the radius of your wheel and fender. Distance between fender mounts is 6-1/2" (same as stock 72-84 FX).
A nice 1/4" counter bore allows you to tuck in 3/8" socket head cap screws for a super clean look.
keep your swing arm and get rid of the outta place straight lines your stock struts create.