Bought a new Z7 this year and it's driving me to the brink of insanity!

I'm grouping field points well and broadheads well but not together. I read all the other posts here and followed the easton archery tuning guide. I shoot a 28" st. epics(400) with 100 gr. wasp fixed blades thru a whisker biscuit @ 53# measured thru an old bow scale (not sure the accuracy) They are 60# limbs turned back a turn and a quarter. I shoot lower poundage because of a rotator cuff tear in Aug. 08 (missed the whole season). The broadheads were flying 5" left and 4" low compared to the fp. I got the height problem to within 3/4 of an inch. However, the guide says that a right handed shooter landing broadheads to the left is an over spine problem. I first tried 125 gr. heads. They landed lower than the 100's but no left/right difference. I then tried moving the biscuit to the right until it hit the cable guard about 1/16" and this brought the broadheads to about 3 1/2"-4" of the fp. Since it didn't remedy the problem i set it back to where it was originally. I then cranked down the limbs to the max presumably 60-63#. this made the broadheads land about 2 1/2" left of fp.
If i look at the chart from easton, @53# i should be shooting a 400 spine arrow. But at 47-51 # they suggest a 500 spine arrow. Is this my over spine problem?
Please don't tell me to shoot a mechanical! I also refuse to sight in for broadheads and never shoot field tips. I truly believe that a well tuned bow with the proper spined arrow will land both together, my last bow did ever time.
Please help before i shoot this bow with my benelli !!!!!