The small white #'s books I have(Chrysler Corporation parts &casting numbers) says 4006630-440 was made 1975-1978.Mabe the -7 means 77'?
What about #'s/codes on the engine ID pad on front of engine?Also like Chryco Psycho said,the engine ser. #'s stamped on pan rail,could help you.
It may have come from a RR but it looks to me to not be an orig. RR engine.The engine ID pad will most times have a year code(as a letter)this info could be helpful.