Small world Bob, the first engine swaped into my bird was a '65 389 from a GTO in 1976. When the 389 came out I gave it to a friend not knowing that I would end up owning that same GTO in the 80s. (The red one pictured in an earlier post.) The friend I gave it to recently past away and that ol' 389 has now returned to me. I'm sure he'd want me to find a good home for it, but the way it's followed me around I'm not sure I could let it go.
It sure ran great in my bird!
The 389s are great engines.