I well add some info. The 200r4 in stock form is weaker then the 700r4 since it came in mostly v6 cars like cutlass's and monte carlos, but it has way better gearing then the 700r4 mostly a better 1st to 2nd shift. It can be built to handle anything now a days. As for the overdrive needing a controller,it is not true its the torque converter that needs the controller as 700r4s and 200r4s have lockup torque converters to help with mpg and heat cruisen down the highway. I have put a couple 700r4s in older cars and I just rewire the trans to lockup the torque converter in 4th using the the 4th gear switch that is built in to the trans and using power from a relay that is powered by the brake switch (to help with 4th gear panic stops).
http://www.700r4.com/tech/tcc/index.shtml They sell a good cheap kit
.............................1st.......2nd....3rd.....4th
Power Glide........ ....1.76......1.0
TH350 ...................2.52.....1.52....1.0
TH400....................2.48.....1.48....1.0
700-R4/4L60...........3.06.....1.63....1.0.... .70
200-R4...................2.74.....1.57....1.0.... .67
4L80E....................2.48.....1.48....1.0.... .75