For interest payments required by this Part covering invoices on purchased goods, property or services which are other than capital in nature, the corporation may use operating revenues, State and local operating assistance funds, State and local tax subsidies, investment income, and any other sources of operating funds which are or may become available for such purpose. For interest payments required by this Part covering invoices on purchased goods, property or services which are of a capital nature, the corporation may use any available governmental capital appropriations, Triborough Bridge and Tunnel Authority Investment Income, MTA Investment Income, and any other sources of capital funds which are or may become available for such purpose.