Thread: How much KR will headers reduce?

I finally got around to scanning my gtp for KR since i bought it. The current mods are AL 104's/CAI/180* stat/U bend delete/3.4 pulley/old DHP ecm. I run 93 octane and am seeing just a hair above 4*kr at WOT. I want to get rid of it the cheapest way possible. I was hoping that maybe a set of headers would make a big difference. If I do the exhaust even though Im trying to stay on the cheap side id rather do the headers than a PLOG or ported manifolds. Any idea as to how much KR headers will reduce? Or should I look into a different option?

Thanks!