I just bought a 14" Magnaflow muffler for my 01 Yukon. I haven't installed it yet. I plan on using the factory pipes w/ the new muffler and tip. I am having second thoughts on the 14" maybe being too loud or having too much drone in the cab. Should I send it back and get the 18"? Buddy of mine has the 14" on a Silverado and it sounds good. I don't know if there would be a difference in sound between the Yukon and Silverado?