I wish you well with the project. My first thoughts are all the electrical wiring. The first thing would be to remove 10 miles of wiring out of the existing car, then rewire it for the 440/trans of choice.
Thats not a bad thing in my opinion.
You just know that none of the factory gauges, ABS, airbags .... You will need to basically redo the dash, Heater/AC Basically I picture first steps would be to remove everything you can not use.
The car would not be much more of a shell to get all the wiring out of it.
Here in my area, the yearly test for registration is a safety inspection for lights, horn, wipers, turn signals .... You could build this car in Texas. There is no inspection for emissions.
What is your actual goal for the car? A Race car or a daily driver? Either way I just see you stripping the car down to rid it of all the useless articles, install the new drive train, including front end of whatever is needed. Then rebuild the Dash with the HVAC system, new dash board & gauges, then complete wiring. Then pack the family up & move to Texas
Just thinking you are going down to a shell to get all the electrical & drive train out. May as well Narrow the rear end, tub the wheel wells, add a 833 4spd trans, 440 motor DO ET!