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Yes, when all timing marks are lined up then everything will be set correctly and that's all that is necessary. To install the belt and set the cam timing you'll just need to ensure that all timing marks line up and there is no slack in the belt in any area. After installing the belt and lining up the marks then you'll want to turn the crank clockwise two full revolutions and recheck the marks. As long as all the marks on the sprockets line up with the plate and oil pump and there is no slack between the crank, left cam, water pump and right cam then the valves will be in the correct position in relation to the cams and timing is set correctly.
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