Exhaust stub

[al pushpak]

Hi all, hope this doesn't come across as a daft question but I have an exhaust stub that has been machined/dremmeled out so it is now bigger than the corresponding exhaust port on cylinder,ie it now doesn't match up, would this modification cause any drop in performance or will it not make any difference whatsoever? Thanks for any info.

[hullygully]

as long as its not smaller & you can still seal it up?