Just a guess since no one else is responding to your question. This may be a state assigned number for a replacement engine. 'MVD' could stand for 'Motor Vehicle Division' followed by the rest of the state assigned number. If you can check and see what states it has been titled in you may be closer to an answer. Someone else may have a better answer.

"Nothing astonishes men so much as common sense and plain dealing." - Ralph Waldo Emerson