It's been confusing reading up on what rear axle were used in 1969.
Here's what I read about the 741 case: "1-3/8" small stem pinion (aka. '741')
Carrier casting numbers: 1820657 (1957-1964), 2070741 (1964-1972).
This assembly was typically used in low weight/low horsepower applications through low weight/medium horsepower and high weight/low horsepower applications."
I've read that both the 742 and 489 rear axles were more desired than the 741.