I think I'd want to know if the front suspension could handle the additional weight. Then again, if you got rid of all the computers and wiring, maybe there wouldn't be much weight difference.

Then the next deal would be the brake system. You will need to reroute all the brake lines to eliminate the computer controlled anti lock brake system currently on the car. Its not like the early days when you just bypassed the thing above the rear end and ran a single line to the rear axle. you get to start at the master cylinder and work from there. My concern would be if these massive brakes will work without all the computer assist.
Beyond that, everything electrical inside the car has to be changed to old school. You might want to look at a flood car, clean up the body, trash everything inside of it, and build from there.
Then, as long as you can drive it where you don't need to pass any kind of vehicle inspection or emission testing you might be OK, because it would never pass the visual inspection, let along an actual emission test.

Of course, when you do this, we will all want to watch the process in pictures. Then we will be able to decide if we want to put this muck work into a project like this. Gene