The H words.
Its official copper gaskets and headman headers are not a good combination. I replaced them with good old Mr gasket fiber ones and no leaks. The raised bead on the headman's and the raised bead on the copper gasket don't like up and they leak like hell. Don't waste your money if you have headman headers. I followed this advice http://www.thepontiactransampage.com/headerseal.html and they sealed great.
Its official copper gaskets and headman headers are not a good combination. I replaced them with good old Mr gasket fiber ones and no leaks. The raised bead on the headman's and the raised bead on the copper gasket don't like up and they leak like hell. Don't waste your money if you have headman headers. I followed this advice http://www.thepontiactransampage.com/headerseal.html and they sealed great.