Notwithstanding any other provisions of this act, the following apply:

  (a) Sections 1 through 22 apply only to the estate of a resident or nonresident decedent dying before October 1, 1993 or to a generation-skipping transfer that occurs after December 31, 1992 but before October 1, 1993.

  (b) Sections 31 to 56 apply only to the estate of a resident or nonresident decedent dying after September 30, 1993 or to a generation-skipping transfer that occurs after September 30, 1993.