I was having a senior moment and getting my seventies and nineties mixed up. The article definitely says 78 and on pressure regulator.. Is this a series or model number and not a date?
Do you think the only difference between this and standard valve is that it allows the converter to fill in park?
That's the one, & yes, it's only function is to keep the converter primed & lubed in park...can't answer off top of My head why later regulator is required.. @VOETOM