E-Streets

powdered metal seats sounds lame.If they are, you are not going to heat treat them more than they are, already inserted, without removing them and crossing your fingers. call Edelb and ask. if those are the heads u want run them as is and get back. I run 3418915 340 heads , 1970, since 1995, no hardened seats added, cut to 2.055/1.625" no problem. High quality Manley stainless valves help