[jim_howard_pdx]

Copper is what we use for racing, allows simple disassemby and reassembly at the track. When you win a bracket they often have you pull a head for verification, so copper is a great facilitator.

I use Felpro Steel and Graphite gaskets for my highway car with TrickFlow heads and they last a minimum of 2 years.

I plan to try the new Mr Gasket graphites if they decide to make a set with an oval port to match the headers I use. Right now they only have rectangular, and that is not a good match for me.

Kevin, I have never tried silicone on an exhaust header flange before. Just how long have these silicone gaskets worked for you?

Exhaust temp is between 1100 and 1500 degrees f. Most silicone is rated at 500 to 575 degrees??????

The coefficient of expansion between the head, the header, and the silicone is all wrong. But if it works, I would like to try it next time I blow a gasket and the shops are all closed down. Too bad you have to wait overnight though.....that is a pain.