Good day all. Long story short, when changing out my manifolds and risers to cure an exhaust leak it was discovered that the "replaced" manifolds were never done as indicated when the boat was purchased. With that said, my motors are 2006 inboard 5.7 350 Horizons with approx. 500 hrs. Where the exhaust leak was it took out the center to exhaust ports on the head. Meaning there is material missing. It looks like a head replacement is in order. I'm not a fan of having the area welded and ground down I'd prefer a replacement head. Two questions: 1) One head or two? 2) OEM or aftermarket parts? Thanks for any opinion and information given.