I'm about to make the big step myself.After reading your artical....I went hummmmm what if I cut my 1 3/8" hole saw in half & weld a 12" piece of 1 3/8" pipe between them[making a 13 1/2" hole saw]using the baffle as a guide.And instead twisting & beating,cutting the baffel at the base.I ride a '07 America & I'm hopeing the inside baffel base is sitting less then 12" inside........wish me luck!

..... ''BUT THATS WHAT THE PEOPLE LIKE TO READ ABOUT.....UP IN AMERICA'' Jimmy Buffett