if you have done a transmission swap in the past, then you already know most of what you need to know. the swap itself it fairly straight forward, you just need to change a few parts, AND MAKE SURE THE THROTTLE VALVE CABLE IS ADJUSTED PROPERLY. i emphasize that because i have seen many aod swaps where the adjustment was done wrong, or it was decided to let the trans shop do the adjustment, and an otherwise good aod was burnt up in short order, some didnt even make it to the shop just a few miles down the road. some of the parts you will need for the swap are;
1: a flexplate with 164 teeth, and the right imbalance factor. if you have a pre-81 302, or any 351w/c, then you need a flexplate from a 69 351w with 164 teeth, and an 11.4" converter bolt pattern. if you are using a post 81 302, then you just use a flexplate from an aod equipped 5.0
2: for the early stangs you need a crossmember from windsor-fox.
3: check out
www.shockley.net/holley-AOD.asp for how to adapt the tv cable to a holley, or other 4bbl carb.
4: you can also use a lokar tv cable kit if you want the high buck route.
cost depending on the trans, runs around $1500(max) total if you shop around, and do much of the work yourself. summit racing has the flexplate you need for around $110.