Probate Code § 9004

(a) This part does not apply in any proceeding for administration of a decedent’s estate commenced before July 1, 1988.

(b) The applicable law in effect before July 1, 1988, governing the subject matter of this part continues to apply in any proceeding for administration of a decedent’s estate commenced before July 1, 1988, notwithstanding its repeal by Chapter 923 of the Statutes of 1987.