Get a muffler shop to rebend the piping so that it slopes differently.
one inch in rim isnt going to make or brake ur ride, if youre not bottoming out right now, you'd be riding fine with 15's
* edit. its break. why would he spend money on your 15's and have to pay a shop to rebend his exhaust? why not just buy 16's and not do anything at all except slap em on