I ordered a flowmaster 40 series muffler and the stock muffler in my 99 f150 is longer in length than the flowmaster is. Does this matter, or when you remove the stock muffler, the pipes are longer than what it looks? Also it seems to look as if the stock muffler is welded on, and I have no cutting tools, not really sure what my best bet is. Should I take it to a shop? Will I need to buy myself some clamps?