hi, I just noticed that there is a mismatch between the header and engine on my new 160 gas engine. the exhaust port on the engine is basically larger than the entrance in the tuned pipe header. I suspect this will not give the best gas flow so I wonder if dremelling away a little metal on the intake of the header(chamfering the edges all around) would give measurable improvements on rpm and power. As things is now I see rom for improvement or is there any sensible cause for this mismatch??