Mopar Inheritance

BOY!! Putting a 440 into an A body is not normally "for the novice." So far as the engine, if you can find a cooperative local, and IF you can find documentation on what was put into the engine so far as pistons, cam, heads, you can UNDO that and turn it into a street engine. You might only have to change the cam. Just depends.

You could sell it but even with "ironclad" documentation, you will take a bath on the price, as people will be buying "a pig in a poke." If you do that, "figure on" disassembling the engine to let people examine parts. Pull one head, pan, etc

One of the "first things to do" is wander over to MyMopar and look around that site. There is TONS of archived info, including being able to download free service manuals and other related literature.

MyMopar - Mopar Forums & Information - MyMopar Tools/Reference

Another good information archive is the The 1970 Hamtramck Registry That site has all sorts of archived info

The 1970 Hamtramck Registry Home Page

Last, very sorry about your Dad. My father and I had no such interaction. We got along OK in later years, but my early/ teen years were a mess with him.
I was already leaning that way with the engine. I would be skeptical if I were buying from someone / a motor under similar circumstances. I just don't know what all needs to come out. The shop that worked on it said they didn't keep great records of what all went into it, but knew it was at least 12:1 compression and around 600hp. The paperwork I have so far doesn't list any of that, but I think some of the old parts are being held in the packaging for what he put in the motor. I can hopefully find out a bit more from that. The shop also said that he had a huge cam in there and would definitely have to change the pistons / associated parts (stuff I'm clueless about) if I wanted to "street" it. I think that's how he explained it.

My dad raced a Dart and Duster he put 440's into back in the 80's / 90's and apparently he was trying to do it again, haha. I'll have a shop help me or look at purchasing what I need to get the motor in there safely. Thanks again for reaching out! I'll try to start a thread of this crazy journey.