Beautiful truck. You are lucky to have such a nice, rust-free example.
Many years ago we had a '74 F250 with a plow. Not sure if it was a factory highboy or just mildly lifted, but it was a 360 4-speed, and was a great vehicle. We used it to do snow at the family business, a trucking company, where it cleaned up the parking lots, truck wells, and all that sort of stuff. It did years of good service for us until one night, rather than parking it inside the warehouse (where it would be warm and then snow would stick to the plow more, etc.) we left it outside. Big mistake - apparently someone else thought highly of it, also.