The bracket was the same for 70-74, p/n 3443 877.
There was another part number in the 70 only parts book, p/n 2947 572 for 70 Cuda & Challenger. It was superseded to 3443 877.

According to the 70 only and 70-71 books, Cuda & Challenger used the same bracket for the 70 & 71 model years.
72-74 showed a different bracket was used on the Challenger, p/n 3573 624.