[nu2-72]

Actually I believe they are the same diameter. The differences which are hard to see are the center single mounting bolt. On one shield the indent is inward, on the other it is outward. The guage is heavier on the 3/4 and the 3/4 is notched in the center. I would say they will fit but not positive. I could slip the 1/2 ton onto my 3/4 axle for you. I know that is backwards of what you need but if it goes one way it may go the other.
Well, actually I have a 1/2 ton Blazer 44 axle out there too. I will slip my backing plate over it for you. May take a bit. 10 below 0 today and I am moving slow.