...How much wider do those make the plow when wide open?
Wide open it adds about 25" as each wing is 12" plus a half inch or so on each side for the hinges. Being 2 feet wider is a bit excessive so I don't use it that position often although it works perfect for a quick clean up of those inch or so dustings of snow; plus if I had made the wings shorter it would greatly lessen the effectiveness of them when in the "box" arrangement.
Overall I'm pretty happy with them, if the improvements I made work as well as they seem like they will then I'll be in great shape I have a few ideas of things I'd do differently if I ever build a new set but it's not important enough to rebuild these ones. With 3 settings for each side (well 4 now that they can swing behind the plow) plus the angle settings of the plow itself the configuration options are nearly limitless...well, maybe not limitless but there's too many for my poor math skills this early in the morning
One of my goals was to avoid molesting the original blade too much in order to mount these, it had already been molested by the PO but I don't need to make it worse lol. So, as it sits now I have two 1/4" holes in the end ribs on the back side, barely noticeable, easily welded closed. The mount for the inside end of the front link is welded to the blade face which I didn't want to do but that's also easily ground off and smoothed back to stock.