Exhaust Piping

I bought a 93 stealth es a while ago. I did a custom exhaust system thats works well but i'm thinking of doing a TT conversion, thus i will probably upgrade the exhaust further to a catback dual system. I bought (all 2.5") a 3sx dp, random tech cat, and a magnaflow muffler, with 2.5" piping. I'd like to re-use this stuff when i do the cat back. Anyone see real bigh problems and/or dis-advantages if i was to use all 2.5" stuff for the conversion?