Shorten drive shaft because the 700R4 is longer. Modify or replace with an aftermarket transmission cross-member because the mount is further back.Add a TV cable because it uses a throttle position cable instead of engine vacuum to shift (and it has to be correctly adjusted or the tranny will self destruct. Modify the shifter linkage (aftermarket has the parts) because you now have four forward gears instead of only two. Finally you need to rig up a torque converter lock-up switch to go racing (you need it off to race), or modify the tranny to do it automatically all of the time (engages above 45 all the time).
Metric instead of SAE fasteners (in the tranny and the torque converter), and tubing uses O-rings instead of compression fittings.