Identification on used Mopar Crate 360

I bought a '69 Dart project several years ago that the PO had tired of. It came with a new 380-horse 360 crate motor already under the hood.
My build is still not complete but from the research I've done I found the 380-horse motor came with Magnum heads and the 390-horse version came with the later Magnum R/T heads. Same cam is used in both motors. Oh, and my 380-horse crate motor came with the single-plane M1 intake. The PO put a Holley 770-cfm Street Avenger on it. But, as I said earlier, the build is still ongoing and I still plan on pulling the motor and checking everything out while the body & paint is being done.