[caverman]

Are you saying you already have a 3" cat-back?

If you do and it's connected to the factory headers and cats then the inlet will be a 2.5" on your cat-back.

That's what I was originally saying. Even though you have a 3" cat-back they have to have an 2.5" inlet because the factory headers/cat are 2.5" outlet.

From my understanding the way to get a full 3" system is to buy a complete setup from headers to exhaust tip or have one custom made.

Sounds like the headers would hook up to your cat-back so you may not have to alter anything.

Just be careful of buying from a individual. There was a big header scam that just took place a couple weeks ago. At least one person lost $1,000 and a couple others lost some money trying to buy some wheels from the same guy. PM me if you want to see those links.