I've got subframe connectors on my dart and to my surprise when I jack the car and put it on stands the body still flexes. So what do you suppose is going to happen when you put the loud pedal down with that big, honking, torquey 440? You're going to have more stiffness with that 2 door post (great car, by the way, I like it) but certainly subframe connectors will help. Be sure to weld them to the floor pan, not just the end points.
