No, a transmission from a 1994 Dodge 318 conversion van will almost certainly
not fit in a 1998 Dodge Durango. While both vehicles might use a 318 engine, the transmissions themselves are very different, depending on the specific transmission used in each vehicle. The Durango will likely have a different bolt pattern, different input/output shaft lengths, different bellhousing pattern to match the Durango's engine, and potentially different electronic controls. Even if the transmissions were superficially similar, the differences would likely be significant enough to prevent a swap.
You would need to identify the specific transmission in *both* vehicles (e.g., 727, 46RH, 47RE, etc.) before even considering the possibility, and then carefully compare their specifications to assess compatibility. Even then, a direct swap is highly unlikely without significant modifications (and probably not worth the effort).
