While not exactly applicable, I recently downloaded an article that has a lot of related info. Check out http://mustangsandmore.com/ubbDanJonesC4AODswap.html. Good luck.
What about those gear vendors overdrives. They are pretty pricy, but they might be prett nice. Anybody hve any experience with those? I guess they make 'em for lots of different trannys
The gear vendors units are reportedly tough as nails and are available for anything plus the added bonus of being able to split gears turning a c4 into a six speed auto. The price is pretty high, but if I had the money I'd do it.