Dang it, I hate working this hard! There appear to be a
There are various flavors! It appears that 58-60 Lincoln and Merc used one style, 59/60 Tbird and some 58 Mercs used another. The part numbers seem to be:
B7A-9328-A Valve (vacuum pump check) 1958 Lincoln Mercury
B9S-9328-A Valve (vacuum pump check) 1959/1960 Lincoln Mercury Thunderbird
EDG-17536-C Tube Windshield Wiper Tube (on motor) 58 Mercury 383 w/std trans 59/60 Thunderbird
EDG-16978-A Tube Windshield Wiper Hose tube and clip assy 24" long 58/59 Mercury auto trans exc 2 door and 4 door sedan 58/59/60 Lincoln
372268-S elbow 58/59 Mercury exc 2 door and 4 door sedan 58/59/60 Lincoln.
What this all means is 58 Merc with a stick shift and 58/9 Tbirds did not use an elbow and used a different tube. 58-60 Lincoln and Mercury's exc merc stick shift and sedans (because sedans had a 312 instead of an MEL) used an elbow with the associated tube. I will tell you this was not fun to research as the tubes were obsolete quickly and service was to make something! Note I have re-edited this for clarity. Hawkrod