I've put an AOD into my old test-bed XA, and it was great. They bolt straight up to any 6 bolt bellhousing small block ford block ie. 302/351 windsor, 302/351 cleveland, but not 5 bolt 289 block. And the icing on the cake is that the driveshaft doesn't need to be modified either unless the upgrade is from FMX or C6. They are 0.5 inches loner than a C4, but the slip yoke takes this up easily.
I ran it behind a mild 351C, with a 2.92 diff ratio, and did 1600RPM at 60mph. Plenty of low down grunt too, as the convertor stall at more than 2200RPM (my wheels started spinning at this RPM). I raced my friend in his 78 camaro with 400 cu in and TH350, and I beat him. His car had previously run 15.1.
An AOD built right will handle 750HP. There is heaps of knowledge in USA and Canada - Lentech, Performace Automatic etc. A basic rebuild using some AOD-E parts, and 450HP engines won't cause the trans any problems. But, you must buy the right core, not just any AOD will do. A late model (91-93) 351W unit is the best core.
The only trick is the TV cable/rod adjustment. Get this wrong, and the trans will fry in 50k's. Talk to your local tranny shop on adjustment technique, or surf the web. That's where I found all my info.
I just wish I hadn't sold my AOD trans.