2 inch exhaust??

I am finally going to ditch the flowmasters on the 67 barracuda, going with dynomax ultra flows. I thought the tail pipes looked a little small, so I measured them with calipers and they are 2" diameter from front to back, I measured in several places. They are dual exhaust coming from headers with an H Pipe installed. The motor is a mild built 360, comp 268 cam, air gap intake, J heads, headers, 750 holley carb, MSD distributor and box. Do you guys think it would benefit more to upgrade to a 2-1/2" system or even a 3"? I just feel that the 2" is kind of small for the motor. The pipes are in good shape and everything no leaks, and it would be nice to not have to do a complete new system, but if that is what it needs then I will do it. What do you guys think?