Something doesn't sound right. A normal sized broadhead should not hit the riser on a mid 90's bow. Paper tuning for center shot, just doesn't hack it, in my opinion. If it really had to be set that far in, I would guess that your spine is off significantly. If it isn't spine, I'd start looking for limb twist or a bent riser. In fact, I'd look for those first.

If everything appears okay with the bow, I would bareshaft test some arrows (with field tips) to check for proper spine. Only after I'd made adjustments in draw weight to match the arrow spine, would I find the centershot (by walk-back tuning).