The small block 727's and 904's share identical bolt patterns, but they will ONLY bolt up Mopar small blocks, (including the 5. 2 and 5. 9 Magnum engines up through at least '99 if you do some work to the pilot hole in the crank).
But, the diesel automatic has a completely different bolt pattern than any of the V-8's. I think the only block that has the same bell pattern as the diesel is the V-10, but I am not 100% positive.
Besides, a diesel would probably trash an old 904 in about 10 days. A 727 would last longer if it would fit.
- Sam, 93 Cummins auto/od