you should get the head deck and and block deck spotlessly cleaned. Dishsoap or a degreaser like Simple Green works. Replace oil control O ring. Check the head for warpage by measuring the end width and diagonal lengths of the head using a straight edge.
I would replace the head bolts or get ARP head studs. If you use the latter, then use the ARP lubicant provided and follow their torque down specs and instructions. Always tighten in 2 stages (22 lb ft first time and then 61 lb ft the second time) in the torque sequence prescribed by Honda (start at the center set of 2 bolts vertically, then next set immediately left, then next set immediately right, further left, furthest right...see the Helm's manual diagram). If you are using Honda head bolts, use engine oil to lubricate them and their washers before torqueing down. Obviously the center sset of 2 bolts are the longest. And obviously this is straight out of a Helms manual which is something you should buy.