Newbie trying to fit expansion chamber properly

[VTHokie]

Hey guys,
I have a new expansion chamber from boygofast I slapped on my bike without too much thought, but have been reading more and more about properly fitting it. Does this simply involve grinding the insides of the exhaust manifold and exhaust pipe to match each other as best as possible? Let me know what else I can do to get the most out of this expansion chamber!
Thanks

 

[the chief]

you want everything to match the port on the jug as much as possible, don't forget the gasket if you got a round one. ohterwise yeah, you got it.