BBC Crane Gold Identification Marks
I have a set of Crane Gold rockers for a BBC and I am puzzled by the number and symbol stamped on the lower portion of the rocker body. Some have a Triangle on the left and a -4 on the right. Others may have an O on the left and -12 on the right. All of them are 13-1.7 ratio, but the difference in symbols and numbers at the bottom has me curious since you would think they would be the same.