This is a very old thread, but the value of adding the pivoting is still very useful. A few years ago, I picked up a BX 54" blade and my neighbor, a professional machinist-fabricator went ahead and made the mod for me. He did it a bit different than the OP did, but the result is the same. It works very, very well. Won't be long and it will be time to grunt that sub-hitch assembly back onto the tractor.