Noisy rocker arm?

IMO, If you did the "hand hold" on each rocker that should have quieted a noisy rocker.
Measure the pushrods for a shorty? Visual the rocker cups for wear?
Some old info and tips here may be of use...........
The 1970 Hamtramck Registry - 1973 Chrysler Hustle Stuff Slide Show (Pg 1) (hamtramck-historical.com)