Power Brake Booster Question

Are the brake boosters the same between a 70 Duster with front disc's and a 69 Dart with 10" drums?
I think the booster in my 69 Dart has an internal vacuum leak. I can still drive the car so I don't want to take it off the road. I have another booster from a 70 Duster and that car had front disc brakes. I want to send the Duster booster out for rebuild, then swap it onto my car after it comes back. Just want to make sure they're both the same booster before I spend any money.

Maybe someone with a book can look it up for me?

Thanks,
George