Low RPM Knock - Cam Thrust Plate Installed Wrong?
Well its not likely to cause an oil pressure problem...but if its installed incorrectly its best to get back in and fix it.
The cam retention plate is a machined flat surface on both sides... but it has an "ear" that is supposed to cover over one of the oil galley plugs...not sure if this is just a ford saftey measure or what. Anyway usually the plate is stamped with "back and down" or something to help you orient it correctly. If you got the plate to bolt up, i cant see any reason why it would not function as intended (keep the cam in the bore).
A loud noise that goes away...sounds like a rod or rod bearing issue...