IF the boosters were used somewhat interchangeably by Chrysler, they would all have very similar performance characteristics. Which would be listed in the specs section of the Brake section of the appropriate Chrysler factory service manual. If they were used in different years on the same body series platform, you'd need to look in eacy of the FSMs for the particular model years to compare the specs.
In the times when that Imperial was new/newer, it was somewhat common for people to use cars like that to tow long Airstream travel trailers with. Not specifically for the bigger engines or such, but because the cars were heavier than normal. Add the weight of the trailer to the already heavy car and the result is rear springs that look more like a 3/4-ton pickup truck than a car. Which also meant the brakes were larger-capacty, too. Same with similar Lincolns and some Cadillacs.
Enjoy!
CBODY67