The Thing With Two Heads - I believe this was a TV movie. Starred Roosevelt Grier and Ray Milland, not a great gig for either.
Oh, come on! Just for the sight of Rosie Greer riding a motorcycle with a rubber Ray Milland head on his shoulder this one is worth catching. "They transplanted a WHITE BIGOT'S HEAD onto a SOUL BROTHER'S BODY!" This is the reason the movies were invented.