I have a 55 GMC 102 truck that has front drums that I "think" are oversized. They are measuring 11.170" inside diameter and I cannot find a maximum size anywhere on the internet. The only stamping on the drum is located on the face and it says "W 20" Does this mean they can be bored .200" over the nominal 11.00"? Other than that there are no markings anywhere.
Cannot find any information......
