Noob questions.

So, my father has two 1972 Plymouth Dusters and I am thinking about getting one from him. The one I want is currently only body and chassis. I talked to a friend of mine and he suggested I put a new 5.7L in it. Is this something you guys ever see in a car like the duster? If so, where would I begin to shop for one? I would appreciate any insight to what one would do for a motor in these circumstances.