340 marine engines.

It is easy to identify a reverse rotation Mopar engine IF it is together and "as original." They have a tall adapter that the distributor sits in, with a thrust bearing inside, because the thrust in reverse, tries to push up on the drive gear. ---To the left in the photo

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And if I'm not mistaken (it's been a looong time), the adapter allows use of a 383 distributor (turns opposite of a small block) so the advance mechanism works...