From the factory TF Service Bulletin, running changes for the '74 model year:

"Neutral to Drive shift quality

A-727 only

The N-D package for the A-727 also required the following changes in the rear clutch. The Belleville spring has a higher load and a reduced cone height and thickness. In the clutch retainer, the Belleville spring seat and cushion ring groove were moved forward. The over-all height of the piston was also increased. The piston and Belleville will not service prior models. The clutch retainer will service prior models."