5.0 to eec5

The 94 and later computers were more emissions friendly and less performance friendly units. It is not uncommon for a 94-95 Mustang owner who has a serious desire for more HP to convert their cars to use an 89-93 5.0 Mustang computer. There are even kits to do this little trick.

Your combination of computers would not work well. Emissions control is very much a part of engine control of fuel and spark advance. Trying to crossbreed a whale and an elephant would have more chance of success than a Mitsubishi and Ford interworking computer system.

As far as the trans, a Tremec 3550, TKO or TKO 500/600 would be a better choice.
If you must use an AODE, see http://www.baumannengineering.com/tcs.htm for a controller for it.

If tuned, the 94-95 ecu's are just fine.
They are SEFI, have fan control, and several other elegant features.
The ability to control the AODE is often mentioned as a positive as well

I'm actually running a T4M0 ecu in my n/a 2.3 Mustang daily driver...
So far, it is the best of the 3 ecu's I've run in this car.

What would you gain with the use of 2 ecu's?

Jason is the resident tuning expert, and I would recommend his opinion over mine in this matter. If he can take a TM40 and a tweecer and make it run good on a 4 cylinder, that is expertise worth pursuing.

Sounds like you're doing something other than what I had envisioned...

Try this link...
http://oldfuelinjection.com/?p=3

I'm not hip to all that eec-v jive, so I won't be too much help...
I don't know what sensors the eec-iv and eec-v share.
I don't see any reason why you shouldn't be able to make this work though.