I wouldnt be able to give you a good answer about the spacers, as my E-500 does not have factory limbs, so the spacers changed when I swapped limbs. Also, I had center shot issues after swapping limbs, so the spacers got switched again. Then I put Bowtech Ally cams on it, and they got swapped again!
But from what it sounds like I would try a .050" on the string side, and a .045" on the cable side, that should put your center shot out closer to 7/8". Let us know how you make out.