I had my rear axles & drums redrilled on my 56 when I converted to disc brakes. The fronts were 74 malibu which is standard Chevy pass car 4 3/4 pattern. I took them to a machinist along with a spare car front hub and drum to use for patterns. The edges of the axle hub needs to be ground off slightly to clear the smaller center hole in the car wheel. Installed new studs and bolted them on. It has been working fine for 10 years.
Fred
