Ride it with the dent, then have it repaired or replaced. If you can tell the difference in powerband, ridability, HP or torque, I will give you US $1,000. Just drive by land from your current location to where I am, and I will hand it over by hand.
But seriously, I doubt you will be able to tell while riding, if it is not made that way.
Don't look at some pipe made in fall of 1994 to compare to your recently made pipe.
They may have change at some point. I know several off my bikes have indentions around that area.