Lew - I just put modern bearings in my '50 AD and did not experience any problems. I was told by a representative from a bearing company to put the "clean" hubs in an oven at 250 degrees for 15-20 minutes and keep the races in the freezer over night. Even by heating one hub at a time and working fast, only two races dropped in, and the other two had to be pounded in via a hammer and the side of a short piece of a 2X4. I then used a short piece of brass rod and a hammer to make sure that the races were fully seated (by sight and by sound). Be sure to use the proper size cotter key or your spindle nut will be too loose. Good Luck
