3 or 5 years ago I posted an image of a rear main cap I came across in which somebody had drilled 6 holes and set pins with small slot-like protrusions (to keep the rope seal from turning. In the close-up shot I was able to show 3 of those pins. Whoever did this went to a lot of work. The image is attached.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end