Have a shackle XF-834, and am not sure of the casting # for various shackles. I have researched Palmer on what I thought was an original early Big Twin shackle, but some things aren't consistent with Palmer. It's 6" long, but looks closer to 33/64" wide at the blade. also, it has two grease fittings. Maybe wear and someone adding a grease fitting explain it, but just wanted to know if anyone can share definitive info based on the casting number? Thanks, Vic.