their should be very little diferance in how tight the belt is. The reason it tries to be slack at one point is bc the cam is coming off of a lobe & tries to push the rest of the way off the lobe BUT, if the tensioner is tight their shouldent be any noticable diff. Now as far as rotating it always remember that if you look at the crank you want to make the belt pull directly on the cam not on the tensioner or water pump so that would be counter clockwise.