My 1979 intake manifold is a #B-1262470-B. The PCV valve mounts into the back passenger side of the intake. For some reason, this is one of those parts that I can't seem to find the proper number for.
I found that not all PCV valves are the same size. It tired several brands before I found one that went in without a fight. ( II think it's the bubble flare on the end that is larger on some.)