Brian, I can say I had the exact pain you seem to be having. It seems to be common among those who have bought the Helibars. What I can tell you from my experience is that the Helibars took away any discomfort I had been having.
I really think it was in the grip angle and not so much the height or pull back that made the biggest difference.
Before I had the Helibars, I had tried the Kuryakyn risers, and they didn't help, maybe even made it worse. I was reconsidering whether I would be keeping the F6B if the pain had persisted. Anything over 100 miles or so and I would begin to experience the discomfort.
The Helibars completely removed this issue for me.