There are a few of us that have done the drill the endcap mod, and a few others have pierced the inner baffle. I did the 5- 1/2" holes inbetween the rivets and then refastened the end caps. All it did was to make it run a little richer and a little better sound. As for performance it seemed to make feel a less powerful, although I did the mod during the winter and had to rely on my memory from 6 months before. Redbone just did not feel as fast as it used to.
I say do not to do it, but if you have to have a little better sound you might want to try it.:confused2: