How do you identify the different between a 15.1 and a 17.1 power steering rack?

 

What car is the rack out of. In the fc I Believe there was a 15.2:1 rack which had three lines going to the control valve and a 17.4:1 which had 2. Post a pick and Ill tell you straight away.

 

OK, here is the problem, I got a manual 20.1 and like to change to 15.1 none electronic power rack.
I went to vendors classified and posted a WTB and got answer from Lmill85 stating that he got one.
But ask me “how to tell the racks apart” as he have a few and just want to send the correct one, so.. here we are, He don’t know and I have no clue. Asked for pictures, but so far no response, That’s why I am asking for help to identify them