Power Brake Booster Question

Thanks guys.
Oldcoot- I did exactly that. The car has an idle misfire, so I clamped the booster hose closed and the idle smoothed out. Once I unclamped the hose, the idle speed changed and the misfire was back.

SGBARRACUDA- The boosters appear to be the same size. Both have the "band clamp" around the halves so I think they're the same. I have to clean the Duster one off a bit and see if I can read the numbers on the tag.

Thanks for the help, guys.

George