Header leak

[C6AE]

I have a set of BBK equal length shorties on a 5.0 LX Coupe. I installed them with copper gaskets, but I still think they leak. It wasn't so bad with the off road H pipe as it drown it out. Now that I need a sticker I need to put the cats back in, it's so quiet now you can hear the leak After a search of this site it seems like Dr. Gasket ultra seal are the best gaskets, so I picked up a set. Would it help to put a little RTV on the gaskets too?

 

[GearHd6]

I used the copper gaskets with good luck. You have to really tighten them good and I used Stage 8 locking header bolts because the copper gasket needs a real tight bolt to seal it up.