Well the last year they put the 44 in was 1980 and they started using 10b in 1977 to 1991. Like they said, it is gonna be a 10b unless it has been changed. If it is pretty much round then it is a GM 10b. If it has 8 easily identified flat edges on the cover then it is not a GM 10b. If it looks like that then you should be able to look for the model number on the housing at the bottom right corner if looking at it from the front side with cover on it.