78/82 ford truck question

[Rescue Ram]

Does anyone know if a 6. 9L diesel will directly replace a gas 400 bolted to a 3 sp auto? I have thought about this swap for a while in my two gas Fords...

 

[Philip]

As far as I know the 6. 9 has its own bell housing bolt pattern. That 400 has the 429/460 bell housing pattern.