So many things to consider, biggest is water runoff, one good rain can move a lot fresh dirt. Since we really can't judge your project without pics we are guessing. The right tool is the box blade with rippers, hyd top link will keep you in your seat, and learn how to use draft control. What I did for my slightly sloping driveway to keep from having two eroding ruts was to slop the whole driveway sideways into a parallel drainage ditch that has grass. For my 800 foot driveway I found three low spots that liked to hold water so that drainage goes off to a low spot I created to be a holding area. Every couple years the low spots have to be cleaned out.