73-87 Manual regulator differences - Jason S

[Captkaos]

'73 had smaller rollers (note: some early 1974's had smaller rollers, check) 
74-87 have the same size rollers, but the shaft the handle attaches to is different length. 
73-76 had the same handle shaft length.   
77-87 was a longer handle shaft.

Links to our Store to purchase regulator replacements.
Link to our store for the 1973 Front Door Window Regulator, small roller ONLY

Link to our store for the 1974-76 Front Door Window Regulator, large roller ONLY

Link to our store for the 1977-87(91) Front Door MANUAL Window Regulator

Link to our store for the 1977-87(91) Front Door Power Window Regulator Kit, BOTH DOORS

Here is a photo comparison of the 74-76 (74 K-10) on the right and the 77-87 on the left (83 C-10).
Handle shaft length:

Overall dimensions: