My exhaust guy just hooked up my single in/dual out Magnaflow. I originally requested the dual out pipes be 2 1/2", but he convinced me I would have better luck bending around the spare and factory trailer hitch with 2 1/4". He claims the difference in flow would not be significant. Did I make a mistake by going with the 2 1/4"? It sounds great, and I do notice a "seat of the pants" difference in performance. Also he recommended I put some header tape on the dual out pipes to prevent any problems with tire rot or brake and fuel line damage. Any suggestions as to whether or not this will affect performance or is needed? I have zip tied everything that is close to prevent rubbing against the pipes.