Difference between 71-72 and 73 Brake Boosters

[Gardoco]

Is there a difference between the 71/72 and the '73 Power Brake boosters? If so can anyone tell me what it is?

 

[kcmash]

Is there a difference between the 71/72 and the '73 Power Brake boosters? If so can anyone tell me what it is?

I am not the best at this, but here goes. Mine is an early 71 car(11/70 build date) and it has one of the thinner boosters. It looks to be larger diameter and thinner than other I have seen on 72 and 73 cars.

Anyone else?