A904 SUPER Servo. low/rear question

I do hear a thud. But much less than the air bypassing. i hear. And teying to spin outpuy shaft apears to work. Just whish in had a standard to fo by. Nothing like the modern. 6t70e or 6l80e transmissions. They thunk hard. When applied. Just never done a Chrysler before. New to me.

Guess you are just going to have to find out, but maybe you can find a video with sound so you have a reference.