All '73 440 HP motors got forged cranks, the STD 440 could have either cast or forged at random.

This is the subject of TSB 09-01-73C dated October 11, 1972:
"The standard 440 4-barrel engine will be built with either a forged or cast crankshaft. The cast crankshaft can be identified a different front vibration damper and a stamped letter "E" below the build date on the cylinder block identification pad."

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