BAK9 = Manufacturer and Plant CU1 = Compact Spare 463 = 46th week of 1973
I thought they stopped using Space Savers before the 74 model year. If so, it looks like someone replaced the tire. Does anyone have a picture that shows the markings in a known F78-14 Space Saver? It would be interesting to see if there is a letter "D" stamped in the wheel like the one I have posted above.