I have allways run a tap through the head bolt holes and used the non hard premtex sealer on the bolts and silver paint on copper gaskets with pretty good results. My 235 does weep some with the copper gasket but i can live with it. I may change it because it does loose some compression. I did not know the felpro was a detroit gasket. Oh well i will keep using them.What works for one guy may not for another. smile