B2600i 4x4 Motor Swap????

I think the bell is for Mazda only applications. The transmission is Mazda, and the bell is unique to the gearbox for use with the Mitsubishi 2600.
To the best of my knowledge, Mitsubishi and Chrysler never used the Mazda gearbox.

It probably isn't going to be easy to locate, but junkyards are your best bet.

Mitsubishi and Chrysler did not use the Mazda gearbox, but they did use the Mitsubishi 2.6 Four. From my understanding, Mazda used the Mitsubishi bellhousing on their transmission to use this motor. I am not 100% sure, but I bet the 2.6L Mitsubishi in other applications use the same bellhousing, and therefore will bolt to the B2600 bellhousing, as long as it is a Mitsubishi powered B2600, however, a 2.6L in a front wheel drive application may have a different block casting, and missing mount points for use in a RWD and other things, research and a comparison will have to be done. But, it could be a source of replacement engines for a Mitsubishi powered B2600.