I am restoring a 69 Charger R/T 4-speed and am thinking of adding aftermarket boxes. How common was it for them to be put on these cars? Do they help much? I will be adding frame connectors also. I know they were factory installed on Hemi and convertibles, but another recent thread seems to be implying that all R/T's had them. This car has all original metal right now, has been documented by Govier, and there definatley never was any on this car.