I bought a 920 flex head and have put on a new poly kit, replaced the steel fingers with poly fingers plus all new sections, wear plates and hold downs on the sickle. On the wear plates they have slots that allow for adjustment, my question is wear do I start? Should they all be brought out to just touch the sickle bar or pushed all the way back against the frame. The old ones were all worn uneven. Some had the wear surface worn completely off others hardly at all. Twogun