Was Change Made?

The timing chain cover that was on the engine had a timing mark indicator as part of the cover. The seal could be removed without having to remove the cover. Since I had to replace the cover it really did not matter.
I had to install a bolt on timing mark indicator on the cover that I had to replace. (Broke a mounting bolt ear while torqueing bolt.) The cover I purchased was for 1965 273 and noticed that seal had to be removed from inside of the cover. Think that I will not have to replace seal again, was mainly curious about if and when change had been made. Thanks for the information from everyone!!