Are you trying to say that Gravity is as slow as Light, but that the universe *predicts* the future and therefor Gravity knows where the Sun and the Earth will be in 8.3 minutes and adjusts the orbit accordingly?Come on, let's simply examine observable phenomena. The Earth orbits the Sun of either 8.3 minutes ago or the Sun of right now (or something in between).
Where ever that point resides, from the Sun of 8.3 minutes up to the Sun of this very moment, will let us calculate the speed of Gravity (unless Gravity can somehow be slow *AND* predict where the Sun will be in 8.3 minutes).