i have a set of side exhaust on my 66 corvette that i believe came off a 65 FI, i am returning the car back to an L72 and do not know if i want to reconfigure these 327 2 1/2 inch pipes. based on a previous owners info they are the "real deal" and mint what my question is that the drivers side pipe has a provision for a connection of some type. are these valuble pipes and what does this fitting accomidate? i considered refitting them unless i can find a set of real gm pipes because the sound these old pipes give off but do not want to hack these up if they a rare, your thoughts and input will be appriciated,thank you bill snyder