Flow Tech Afterburner - fully welde dmuff just like a Flomaster and pretty inexpensive. If you want glasspacks, put 'em on. i like the way they sounded in my highschool days. It was quite an attention getter. Matter of fact i have some footage of it (can hear it running) i'll try and get put on a wav file or video file so you can hear it. Like I said, the longer the glasspack, the deeper, throatier (and longer lasting, less raspy) they will be.