Word if you put 200 shots on the stock ls block of an lsvtec motor you can kiss your engine good bye. It won't last long. As far as the header is considered, most mainstream headers that bolt right up will only give you 3-5hp tops. The more high end header by JUN, TODA etc. will cost upwards a grand and give maybe 7-10hp. Not sure why, but this is what I have heard. Stainless over ceramic? Don't think it really matters.