This is a picture taken from my ’77, a few moments ago. It has a slightly different design than yours.
There are a few different designs of the weights they have used over the years.
The black arrows show where and direction your weight bolted onto the transmission tail housing (yours only used the last two bolt holes).
I do know that Chrysler spent a lot of money to design, make and install those weights and I’m sure they had a very good reason to do so.
Now with that said, I have forgotten to install my share of them and hadn’t had a single customer complain about it.
Also, I have never re-installed one on my own vehicles, either. I can’t say I missed it or if it is an issue, then I hadn’t ever noticed it being there (or not being there).
It might be one of those things that effects maybe 10% of cars and I might have just been lucky to have not messed with one of that 10% - maybe (me shrugs).
Note: they do make a great paperweight and/or door stop.
BudW