i got a 3.0 with a flowmaster muffler and K&N FIPK on it. what is next on my list of mods to the engine is headers. I'm looking at a set of downey ones or a set i was in Proformance products. Does anyone have any suggestions on which i should get. The proformance products set said that they are most effective at 2000-3000 rmps instead of 4000-5000 rpms like most others.oh yeah my 4 runner is a stick too not and auto. Thanks