Welcom
grym. OO6 and I are the only sane ones here because hes a double agent, and I'm on medication. )I'm okay as long as I've had my medication, aren't I OO6?)
So sit back, relax, and let us help you turn your ride into yet another sixcylinder art form...
The aod never made it to the 200/250 in-line sixes, but there is a 200 block which can be modified fairly easily to fit one.
See this link here
http://fordsix.com/bigbell.html on 200 big bell to FMX/AOD/C4 OR or C5 transmissions.
Note that the little 200 has a circle of 2.75" for those eight bolts which hold the flexplate on the crankshaft, while V8's and 250's have a 3" circle spacing for its 8 bolts. V8's have Detroit Unbalance...external balancing, but sixes need none, and running an unmodifed V8 flexplate will most likely send a six to an early grave.
The 250 pre 1980 Granada 250 six can take a V8 AOD as is, as long as you find the right flex-plate (Either 300 EFI truck or a similar 5.0 V8 flex plate with the unbalance removed).
The little 200 is an engine of some potential. The first aero T-birds had 'em as a base engine, with the 3.8 as the step up, then the 5.0, and later, the 2.3 OHC four. But a 83 hp or so emissions legal 200 isn't good with 3200 pounds.
The 250 is a good option, if you can cut and shut a 200 'sump bump' from an earlier T-bird or Mustang III (Fox). But there is a lot to it engine mount wise, and the cross-members varied between engines.
Keep asking some questions, and wait for some other advice to come through. Have a read of this. Jack Collins replied to this Christmas day link, and was a was a huge help on this one
http://fordsix.com/forum/viewtopic.php?t=1085&highlight=250+fox