Ind. Code § 20-27-4-8

Sec. 8. This chapter does not affect the validity or legality of a negotiable instrument, conditional sales contract, purchase money mortgage contract, or promissory note executed and delivered before July 1, 1965, by a school corporation and given for the purchase of a school bus in accordance with Indiana law that was specifically repealed or repealed by implication by Acts 1965, c.259.