A 327 in a 1955 Chev would be a hot-rod transplant, and the timing would be custom for that particular engine build.
It would be ......BTDC, anyway.
My Cousin Vinnie voir dire scene:
How many kids today know about timing advance, ignition points, and what a timing light is? I am old.
In my youth I could tear an engine apart and work on it. With all the electronics on a modern engine today I can not. However, these new engines are masterpieces of engineering relative to efficiency, power, and low emissions.