I have had both an 87 bronco II and 87 Ranger, BOTH with the engines out side by side and inspected the cross members. I saw no differences between the two.
the 4r70w I believe is the Modular pattern, and the bell in integrated into the case- not removable like the C4 is. the Windsor bolt pattern and Modular bolt pattern are not the same. I have not seen an adapter plate for the modular pattern to 2.3(lima), whereas Canfield has already produced the Windsor to 2.3(lima)
You can choose to do whatever you like, I was just suggesting the simple route- AOD gives you plenty of strength and overdrive, without the need for electronic control.
If it were me, I would find an AOD with the 302(Windsor) bell, buy canfield's adapter and be done with it. Monster transmissions offers a 4x4 AOD for about $1000. How much HP do you want to support? (sorry, missed your last post. I still would choose the AOD for 500HP at the flywheel with some internal modifications)