My family's shop had a franchise in the 50's and 60's, installing add-on air conditioners. Mark IV was the most popular one, but FrigiKing and Climatic Air were also popular brands. Practically all the add-on units used York or Tecumseh 2-cylinder aluminum housing compressors, with adapter kits for specific types of engines. The under-dash units were almost all the same, regardless of application. We would start on an installation job at 8:00 AM, and usually drive to lunch in the air-conditioned car, then install another one in the afternoon.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!