Cragar SS lug nut trouble
IMO, the minute washer faces on these 7/16" Cragar SS lugs working against the Cragar supplied washers are too small to be reliable for holding torque. Doesn't take much to start digging into the washers. Couple that with any wear on the studs over the years you may be constantly re-torquing.
The older ones from the late '70s were no better.