Very small trace amount of antifreeze in my cylynder head.

I have extremely good condition Lincoln 4.6 upon changing spark plugs after a indicated cylinder # 7 misfire, I found very small trace amount of antifreeze in two cylinders 7@8 engine runs perfect now, I have no residue on bottom of oil fill cap 0 milky residue on dip stick, and 0 oil in anti freeze are there any things I can do to to retard possible head gasket problems?