So I have an 04 wrx. it has a cobb stage 2 tune. Full catless exhaust. I'm interested in aftermarket cams but my engine is stock. I also don't wanna lose any low end power because I don't have alot to start with. Would cams make it worse? would I see and gain of having cams with a stock motor? What if I bore my head's and put oversized valves in? I love the sound of stage 2 cams. Any advice or input would be helpful.