I do not know which size of angle supply 1/2 inch or 3/8 inch to buy to install with a new Kohler Bancroft monoblock lavatory faucet.Kohler K-10579-4-SN Bancroft Monoblock Lavatory Faucet With Escutcheon And Lever Handles. I called Kohler and they said they did not know. Any direction please. This is a remodel in a 1938 house. Thank you