What happens when you reach 4700 does it seem like it lays over? How strong is it pulling ? Do the revs climb quickly up to that point and just stop or does it just work up to 4700 slowly? What valve springs and lifters are you using and are the springs set at the correct height? How did you adjust the lifters? 1.5 pounds of fuel pressure at WOT seems low to me. I would think you would want 5-6 pounds. What diameter fuel line are you using? How about the exhaust? Is it above transom or below? Have you changed props? And my last question is what sort of RPM did the old motor pull?

Pat