If the block (383 or 440) has these bosses you can use the A-Body 383 mount bracket which was also used on 1965 C-Bodies with a 383 in them.



This is the bracket.


Our 69 factory 383 Dart GTS has a 400 block based 451 in it using the factory 383 mount bracket set up.

Before the current 451 I has put a 440 in it using the factory K-Frame.

I'm not sure if this an original 440 mount bracket or a modified 383 bracket.
I traded a spare 383 bracket of a 65 Chrysler for it from a guy that took a 440 out of his Dart GTS to put back in a 383 since it was a originally 383 4 speed Triple Black GTS.
He sold that car to another buddy, who knowing him will be flipping it soon. lol