Those are standard-cab SD70s, which were the last power delivered to Conrail. They were built to NS specifications. The SD70MACs which came a few months before them were built to CSX specs. According to http://crcyc.railfan.net/locos/emd/sdindex.html the SD70MACs arrived between 03/98 and 06/98, the SD70s between 07/98 and 11/98. Both were originally ordered as more SD80MACs, but neither CSX nor NS wanted more of those.
Thanks for the additional info! Yeah, I vaguely remember something about the roads opting to take something other than CR's SD80MAC's that hadn't been delivered.