Did you verify TDC on your balancer and dampener to insure your reading the actual total timing? If not you should, if so have you tried less timing yet? If not I would
I haven't built a stock stroke, or stroker, 440 motor with the TF240 heads yet so maybe those heads will make more power at 38 degrees total timing
Let us know how your doing as you go faster and quicker, that will help others on here