I wanted to a muffler for my Excursion, I was looking at the 70 Series Flowmaster, because its pretty quiet - the wife has to drive it too! Anyone use this muffler? Also what is the diamiter inlet/outlet for the V-10 Excusion?

B.T.W. - Should i get a full cat-back system? I know that the EXPY doesn't gain really any HP from exhaust, and was wondering if this was true for the Excursion? Whats a good semi quiet cat back sys?