As a dealer for tti I have seen this has happened many times, I am unsure where you purchased your exhaust from but the vendor should have asked you "what headers are you connecting the exhaust to", and if it was tti that sold you them, shame shame on them.....
tti has the adapters for a few of the different header mfg and size headers to help fit it all together, header lengths very from one manufacture to another.
Another problem that happends too often is someone wants to purchase the exhaust and not the exhaust and mufflers because they want to use there own and, guess what, the exhaust are designed in length to use there muffler, if your muffler is 1" too short, they don't butt up and fit correctly......
Nick