Re: quick ? DO dented pipes/HEADERS MESS WITH PERFORMANCE AND is this dent something
Well it depends on what you mean by "mess with performance". Any alteration will make the pipe perform different from the design. Believe it or not the better pipe guys spend a lot of time tuning the pipe to provide a smooth power increase. However we all ride with things that aren't exactly perfect and this may only cost you a few tolerable spikes in the power curve and some peak hp. On the other hand dents in the header pipes are worse because that's were the hot gasses are moving the fastest and are most easily disrupted. Slow these down and the pulse frequency might be disturbed, which would be a performance issue. I would also recommend a dyno tune as this pipe is probably not moving the exhaust gas it's supposed to and this will alter the proper air fuel settings. I would definitely try to pull those dents out, as they are also deep enough to be potential structural issues with the header.
Not sure how to pop those dents out. You could put a screw in the header then yank it out like a dent in a car I suppose (then patch the screw hole of course). On the other hand you can just try it and see what happens, as I doubt you will damage the engine. Tools are a socket set and a wrench set. I also use a rubber mallet when I did mine (gen II though).
You asked, that's my opinion!