exhaust pipe diameter for a mildly modified 340

Yup, when the time comes i'll install them.The complete exhaust came off a 340 Dart with the same
...549, and ...553 manifolds that i will use. The previous owner/friend restored a show quality numbers
matching 69 340 4speed convertible. I think there may only have been about 50 of those cars made and
these replacement pipes had no business on that car but it won't matter on mine.