Your first investment is the FE-to-trans adapter. If you can find an adapter to a modular trans (e.g., 4.6), then your options open much farther. I say this because you can get the later 4R70W / 75W in wrecking yards, working, with warranties for cheap. Some are small-block pattern, but most are modular. Add $600 for a controller and harness, and you're almost there. The older AODs are getting tough to find in usable shape, and the ability to control shifting character for your specific vehicle and driving style is a big plus. You can even tell some controllers to use whatever shifter pattern you have.
For example, I checked local municipality auctions for cars and transmissions. I found a 2008 police car with service logs for my buddy, showing the trans was factory
remanufactured less than 40K miles back. He got the car for $1100, took the trans, converter, wiring, cooler, yoke and more, then sold the rest for $700. Added the controller for around $400 and modded the harness (saved $150). With fresh synthetic fluid, filter, and odds 'n ends, the whole conversion was under $1200 to driving away. Even a local rebuild is half of one of the good online outfits, with someone local to bark at. Or, do a rebuild yourself for cheeeap. Lots of options for better gear at reasonable prices. More options is more awesome. Do your thing!
