Cleanup of Standard Cost records

FIFO is the recommended Inventory part Valuation Method for our organizational users by the Finance Department. However, we noticed that some of the part creators in IFS in the past have incorrectly created parts with Standard Cost with ‘Cost Per Part’  at Cost Level. There are already transactions in IFS with this incorrect valuation method. (There are couple of Parts with ‘Cost Per Lot Batch’ at Cost level as well) . 

Now I need to change those parts’ Inventory valuation Method back to FIFO. What type of impact will it have if I change them directly in the Inventory Part window? (Plan is to have FIFO with ‘Cost Per Part’ for the majority of the parts and Weighted Average with ‘Cost Per Lot Batch’ for the rest) 

One of the special scenarios we use is that we receive via ‘Receive Inventory Part’ the project leftover quantities (since they were previously paid by the project) at zero cost which reduces the inventory unit cost overall. But when we issue the same parts I guess the unit cost is balanced. I hope this practice will not be impacted here.