From my experience, with stock cam and advance characteristics if the static timing is advanced more than 4 deg from factory spec you may get more pep at light load acceleration, slight milage improvement, less smooth idle, less power and rpm at high throttle opening/max revs.
I would limit the extra static advance to 4-6 deg.Most of these engines used 4 deg static so it sounds like you are advanced by 11.Back it up to original specs and try it you may be pleasantly surprised.
