i dont understand there are so many bsers out there every 3.8 litre ive ever looked at come from the factory with headers and considering how many millions and millions of these engines out there if you dont have headers already you could probably get some for free good luck theses engines are awesome i would almost catagorize these engine with the old slant sixes ive seen so many that will still smoke the tires after 400k plus kms and never had a valve cover removed for any reason LOVE em im going to do mine ill post my experiences and gains thanx