I use my 3 pt blade. I plow about a mile of gravel roads several times a year. One of the problems with plowing on gravel in our area is that the ground here does not freeze hard all winter. If you use the grading blade by itself, you are often throwing gravel to the side of the road with snow. I have been bolting a 2 x 10 PT board to my blade. My board is 2’ longer than my blade so that I have some leeway beyond my tire width. This allows me to plow to the edge of the road without running my tractor real close to the edge of the road. The board also is a blunt edge rather than a cutting edge, so does not throw gravel with the snow. The result for me is that I am able to plow almost down to the gravel without moving the gravel. I just drilled 2 holes in my blade, and attach the board with 2 bolts. When I want to use the blade for grading in the spring, I just take off the board. I believe I heard about this from someone on this forum, but I can’t remember who.
There are others who have fashioned PVC to on their cutting edge or steel pipe to bolt on. The wood board works well for me. I have a much smaller tractor than you, but don’t see why it wouldn’t work for yours.
Jack