Powerglide
Although the Powerglide 2-speed automatic transmission was ordered and reported under RPO M35 for all years it was available, there were many variations of the transmission depending on which engine it was being installed behind. For example, in 1966 and 1967 there were no fewer than 7 versions for each year.
The transmission date was stamped into the oil pan itself on the passenger side.

T - Toledo
1129 - November 29 (1965)
N - Night shift

T - Toledo
0214 - February 14 (1966)
D - Day shift