No problem at all with clearance, nothing to be gained by doing it. Against federal law to remove the cats so no muffler shop will/should do it. You want it loud, get different mufflers.
It sure is against the Federal law, just may not be inforced where you are. Also why most shops will not remove them.Its not against the federal law....the law varies state to state...like I am from Ohio and we do not have to have cats.