Inner and Outer Rocker Replacement

Can anyone with a 71 Dart verify for me the width from outside front rail to outside front rail where it's welded to the torsion crossmember? Mine is completely rotted away right under the driver side floor pan. My front measurement at the core support was 34 1/8", and under the firewall was 34 1/4". Just curious if they are supposed to match up or taper outward. Any help would be appreciated. Thanks