until
June 30, 1984, to a loan of money or other extension of credit between a plan and a party in interest under a binding contract in effect on
July 1, 1974 (or pursuant to renewals of such a contract), if such loan or other extension of credit remains at least as favorable to the plan as an arm’s-length transaction with an unrelated party would be, and if the execution of the contract, the making of the loan, or the extension of credit was not, at the time of such execution, making, or extension, a prohibited transaction (within the meaning of
section 503(b) of title 26 or the corresponding provisions of prior law);