Doc, piece of advice... Finish one project at a time. Enjoy car for a time THEN dive into the next one.
Your easiest engine swap would be 340 or 360. 383 and 440 have other issues in a swap that complicate things.
Not to mention... YOUR IN CALIFONIA
Smog requirements go with the engine. IE put a 74 engine in a 67 and you have to meet 74 smog on the engine.
Maybe CA changed how it does smog on older cars but that's how it was when I lived there.