An engine that is compatible with the 1984 Cadillac 4.1 is the Olds 307. Another possibility is the Vortex 350.
Thomas the Tank Engine and Friends - 1984 Mud Glorious Mud 10-41 is rated/received certificates of: Australia:G
Jeopardy - 1984 1-41 was released on: USA: 5 November 1984
Super Password - 1984 1-41 was released on: USA: 19 November 1984
Jeopardy - 1984 2-41 was released on: USA: 4 November 1985
Jeopardy - 1984 4-41 was released on: USA: 2 November 1987
Jeopardy - 1984 5-41 was released on: USA: 31 October 1988
Jeopardy - 1984 6-41 was released on: USA: 30 October 1989
Jeopardy - 1984 7-41 was released on: USA: 29 October 1990
Jeopardy - 1984 8-41 was released on: USA: 28 October 1991
Jeopardy - 1984 9-41 was released on: USA: 2 November 1992
Jeopardy - 1984 10-41 was released on: USA: 1 November 1993
Jeopardy - 1984 11-41 was released on: USA: 31 October 1994