68 cuda exhaust pipe routing

I think .youre right about that. from the pictures and videos I have looked at online it really doesn't look too complicated to but that exhaust Together. the only other question I have is can you squeeze a two and a quarter pipe by the passenger side of the gas tank is can you squeeze a two and a quarter pipe

TTI makes a 2 1/2" pipe past the gas tank. It's close. I have it on my car going to factory-like stainless tips that are 2 1/2".

On a 67 A-body it might interfere with the 67 only side to side gas tank strap, which you don't/shouldn't have.