I installed a Kami header and the gasket between the primaries and the collector keeps blowing out on me. I tried dead soft Aluminium, and paper (grifite impregnated) both failed in a day. Now I'm trying a copper gasket. I heated up the header and re torqued it, so hopefully this seals. What is everyone else using? What comes with the header? I bought the header used. I did check to see if the flange was flat and they were, so I'm stumped right now.

 

anyone?

 

back in the days when I had that header I ended up welding the two halfs together

 

I made a post about this somewhere.

Here's some tips:
Get the 'Mr Gasket' copper 2.5" 3 bolt gasket and 3 Grade' 8' 3/8" x 1 3/4" bolts with spring washers , flat washers and nuts. ( Not soft Home Cheapo bolts)
Torque to 40 ft lbs then run the car for a couple of days ( heat up and cool down several times)
Then re-torque to 45ft lbs. I have done tons for these headers and never had a problem using this method.