A friend of mine just replaced a rear main seal in a 312 (year unknown). The seal in the car was a newer rubber seal that had failed after not so many miles. In the process of replacing the seal (crank in, engine out) he encountered something preventing the seal from turning in the block. He pulled the crank out and found a pin in the block, presumably to hold a rope seal from turning.

This was the first time he encountered this, and he has replaced seal in a number of Y's.

Is this something ford did or was it something that some one else might have done? I guess some small blocks (289/302's) had a pin in the cap, but never seen one in the block

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ