For leveling with a rake, you might also look at gauge wheels. The gauge wheels will allow the tines to dig into high spots, and pass straight over low spots allowing material to be deposited, much like a road grader does. Without them, the tines bite into the earth will be constant if you float the 3PH so no carried material will be dropped into the holes and the tines might even dig in more in the holes. If you set a specific height with the 3PH, the tine bite will really be effected by the tractor angle. IE: if the front wheels of the tractor go into a depression, the rake will lift off and dump a pile of material. If your front wheels go up onto a rise, the rake will dig in more and leave a depression. Gauge wheels and a floated 3PH prevent this and more smoothly move the high spots into the low spots.
A box blade can accomplish the same thing as it rides on it's sidewalls and shaves off the highs and fills in the lows.
You will also find that the rake tends to separate rocks and bring them to the surface.
Good luck.