66 Barracuda dual exhaust ?
I did not modify the cross member.
2.25" duals starting with the stock size pipe,
off the 1964 V8 factory manifolds.
The Midas Muffler shop in Albany NY did the work for me. :) I brought the Dynomax Super Turbo mufflers with me.
http://www.youtube.com/watch?v=Ud8mci4rjFU