I tried searching the forums no luck
just curious about wheel cylinders parts stores list upper and lower cylinders but the both look the same and I can put the old ones on either side and they fit ?

 

This does go back a bit.
I believe there is a line that goes from the lower wheel cyl to the upper cyl. Don't remember if both had bleeder screws or not. If not , then the one with the bleeder has to go on the top.
I believe the only thing you need to watch for is that the openings for the line have to go in the right place to make the connection.

 

Ty sir