2WD Blazer NEED SOME HELP HERE!!!

[MIKEYV8]

Hey you guys out there!
I have a strange question for you!
I currently own 2 1978 and a 1981 2wd blazer.
One of the '78 is leaking oil out of a little hole in the center of the slip/yoke that goes into the back of the TH350 transmission.
Now....I talked to some people who say that the hole should not be in the
yoke at the first place??
But....all of my 3 blazer 2wd have the hole in the yoke!!
Now, who knows if this is standard on a 2wd blazer and can tell me why the oil is leaking out of it by one of them??
It would be GREAT if you could check your 2wd blazer to see if the hole is there!
It would even be GREATER!! if you could post a picture of it for me!!
THANKS very much!!!
Mike.