Some classes specify "No collector headers"
Some tracks require mufflers, hard to do with zoomies
Balence the weight difference between the two and power advange evens out
Whose to say that an off the shelf set of C-H is right for your combination
Zoomies work better for blown application
The only set-up is to make a set of covers to keep rocks from gitting into the exhaust ports
Cams dont care if you run zoomies or not. If they did, every cam maker would have cams listed for zoomies