The Kia FE3 already bolts to the Mazda B2000 and B2200 transmissions.
I am unsure if it bolts up to the Mazda B2600 or B2600i transmissions.
There was talk a while back about being able to bolt a B2200 engine into a B2600i, or vice versa. There was mention of using a ford flywheel with maybe some modifications. But as far as I know its never actually been done. Search some about the G6 transmission (from the B2600i)