What kind of header gaskets are you guys using? My wife and I went for a ride this morning, and we heard a sound like something flapping in the air i.e. an exhaust leak. I tightened the H-pipe bolts, and the header which bolts which on the drivers side were very loose. I thought that would do it, and it did make it better, but still there. At first you could hear it at idle in the driveway, but now I only hear it on the drivers side while driving in gear when you hit the gas. I've had a loose rocker before, and it doesn't sound like that, and I also took the belt off and started it to see if it was an accessory making the noise. Right now I am using the header gaskets that were in the gasket kit I had (not a felpro kit). Should I go with the copper gaskets. Oh yeah it's aluminum heads. Thanks guys...