I second that the 1/2 ton axle of the same vintage will bolt in. I wanted 5 lug disc brakes for my 52 3/4 ton truck so I swapped out the 3/4 ton front axle for a 52 1/2 ton axle I got with my truck when I bought it. Was the easiest swap I ever did and all I swapped was the axle. The 3/4 ton steering and suspension parts all bolted/mounted up to 1/2 axle no problem. The only difference I seen is the width of the 1/2 ton axle is slightly smaller than the 3/4 ton axle, just about a inch or two. The distance from center of leaf spring mount pad to center of leaf spring mount pad is the same on both.
