PART NO.  SPL.PAGE  DESCRIPTION                                                           
14G3722   15.N.9    Outer casing - short end (wiper motor) - (electrical, 1500)
14G3722   TC.N.11   Casing -short end (outer) -(wiper motor, electrical, Twin Cam)
14G3722   16.N.13   Casing short end (Outer) =-wiper motor) - (electrical, 1600)
AHH5410   15.N.9    Outer casing -wheelbox to motor (wiper motor)
AHH5410   16.N.13   Casing -wheelbox to motor (outer) -(wiper motor, 1600 and 1600-MK-II)
AHH5410   TC.N.11   Casing -wheelbox to motor (outer) -(flasher-horn controls, electrical,
    Twin Cam)
AHH5411   16.N.13   Casing -wheelbox to wheelbox (outer) -(wiper motor, 1600 and
    1600-MK-II)
AHH5411   15.N.9    Outer casing -wheelbox to wheelbox (wiper motor)
AHH5411   TC.N.11   Casing -wheelbox to wheelbox (outer) -(wiper motor, electrical, Twin
    Cam)

Notice Wiper Drive Outer Casings:
Item 14 - AHH5410 Outer casing -wheelbox to motor
Item 15 - AHH5411 Outer casing -wheelbox to wheelbox
Item 16 - 14G3722   Outer casing -short end



Casing Length (including flred ends):
Item 14 - AHH5410 = 16.44 inches
Item 15 - AHH5411 = 12.75 inches *
Item 16 - 14G3722  = 2.50 inches

* Many people report mesurement of the AHH5411 center casing to be 13-5/8 inches long.
I have found (via the School Of Hard Knocks) that it works much better when shortened to 12-3/4 inches long.
Find more information and more pictures in tech articles
ET-113A.htm Wiper Wheel Box Maintenance, and
ET-113W.htm Wiper Wheelboxes and Drive Casings