OK I made a mistake, isn't the first time and won't be the last, <img src="/forums/images/graemlins/scared.gif" alt="" /> I meant head studs not shoulder bolts. I want to use head bolts not studs. Use the 4.2 push rods or 4.0 push rods on the 4.0 hean conversiom I have read it both ways but what does the real world say?