does my add or website say anything about heads,engines? i just do manifolds and i do a very good job of it.i have manifolds running around on some very prestigious hudsons. go over to the het site and ask around. if my manifolds fail due to my welding ability. i fix it.and if i fix it,it's not a failure.a failure is when the producct or service is no longer viable. and i really don't think i should have to defend myself in an open forum . if you know mike yoder of kansas kustoms, call him up and check my ability.