atm im looking at possibly getting a set of extractors, as of now i have no engine mods, i think theres a mod you can do with changing the cam n head to a previous model and it imrpoves peformance wich im looking at becouse it would technically be stock as there are no aftermarket parts, as i am still a P Plater for another 5 months. Altho i do have a 2.5" Lukey Catback System, is it better to go with a lukey extractors or what also atm my cats are fine but are they worth upgrading or even to au ones?