The A is the profile/shape, a B profile belt won't fit an A profile pulley right.Yes, the first number is the belt width, the A means frOck knows what, and the last number is the length.
I've seen different brand/style alternators (with different output) on different engines in full sized Holdens, is the same true for Toranas? A different alternator may have a slightly different sized pulley which would obviously change the belt length slightly. Clearly the A/C part is a mis-print.