I agree that stock ones were 2.25" and the tips fit inside the tail pipe.
I have got to think that if you have an NOS system with pipes that small, there has to be some sort of an error. NOS stuff is not always what it is cracked up to be.
A lot of people don't know that NOS parts can be WRONG and/or be correct but fit poorly. For instance, a 69 Barracuda is going down the assembly line in 1969, and the RF fender just will not fit. That part would not be thrown away. It would get sent to a Chrysler parts warehouse and sold as a new Chrysler part. Whoever bought it would likely do the necessary tweaking to get it to fit. OR that part sat around somewhere for 50 years and is sold as an NOS part. You pay $1,000 on an NOS fender that fits poorly. If you are paying a shop to do the restoration $100 per hour, and they spend 6 hours getting it to fit nicely, that's another $600.
