best 912 exhaust

[Jerome Ryals]

What is your opinion on the best exhaust system for our early model 912's. One if my daughters has a friend that is an aircooled vw guy and he just put a tuned exhaust system on one of his vw's and it really sounds good. I've got Bursch systems on both of my 912's muffled but I also have a stinger that I run on them once and a while just to wake the neighborhood up. Anyway I have looked high and low but nothing like what this kid has on his vw. Any help would be appreciated. Thanks, Jerome.
(I don't care about heater boxes)