As Richard suggested, I'll definitely take those measurements and call the vendor. Now this is real rookie question from me. I requested 7/16 stud holes, for the heads, from Dart so would I be safe to assume the rocker studs they gave me would also be 7/16 as well? I'd not think they would machine 7/16 holes for the head studs and machine something different for the rocker stud holes, but like I said this is a rookie question on my part. If the answer is yes, then I have a question, just to satisfy my trivial curiosity. Could I still run 3/8 guide plates and rods on 7/16 rocker studs (I would think so).