I installed Boostbrothers 321 stainless headers on my 04 SC 5.4. 1 month later they both have a small leak that isnt as noticable after she heats up but will probably get worse. they have a 1 piece 3/8 flange and a laminated metal gasket. im afraid to tighten them any more as the stock torque is 20lbs. any ideas, has anyone used stock metal gaskets with headers?

 

^ Right there is your problem. You need to get a set of good gaskets and locking header bolts.

 

x2


since it's probably the el cheapo gasket VS the header