Just wondering how big a difference there is between the exhaust on a stock F150 & a Lightning or a Harley F150. I've got a '98 that will soon see a new flowmaster. The stock muffler is HUGE! Seems like I heard that the Lightning has a smaller muffler, but could this be the only thing different? Not sure about the HD's. I just know they sound much better than stock trucks I have heard.