360 crank knurling?

Aren't those cranks for the full face rear seal? It seems like none of the newer engines have the 2 piece seal anymore.
Not sure about the full face seals but this block has the two piece ( orange ) seal so that tells me the age of its original assembly.
Im obviously out of the loop since Ive learned so much here.
I knew about the old rope seals but now I know about the knurling and the timelines when it was used.