I am not sure what the original size was, but I do know what is suitable for cranking the 351C. I recently replaced my battery connections due to poor connector crimping with #4 AWG cable. Make sure you are particular about how many strands make-up the wire size. Some cheap stuff has only a few strands and is not as flexible as a better quality. This will support any of the starter and battery combinations that are used on the Pantera.