So I have a chance at a deal on a V&H Pro Pipe from an 05 Dyna. Is the only difference in the later model the addition of O2 sensor bungs?

 

The O2 sensor bungs and the bracket to mount to the transmission are different. It isn't too much work to modify the bracket or build a new one. You can buy the O2 bungs to weld into the pipes too.

 

Panimal is exactly right.

The pipes themselves will bolt right up, it is just the mount that will need some modification. I went with newer pipes on my 05 so I could run o2 sensors for the ThunderMax autotuner.

You can always plug the sensor bung on the newer pipes if you do not have an ECM that can utilize them, no big deal, except the pro-pipe bung location sucks.