Mine is a 73 and it didn't have it.
Probably got swapped for an older valve body at some point in it's life.
Point is, you have to do a visual on the VB to know for sure.
.
Not that I'm disagreeing, but to my knowledge, all the a-500s are going to have it, seeing it's an 88-95 thing. The a904 and a-500 valve bodies don't swap. So if your gonna get covered in red oil, it should be more about cleaning the valve body because it isn't working right, then if it has PTKD or not..