Savarez GRN640R Guitarron Normal Tension

I recently had a customer bring a guitarron to me for repair. The headstock had snapped off in the bag since the last time he'd played it. Not knowing anything about these guitars I researched strings. The strings he had on the instrument were, he told me later, from a standup bass. Way too massive of this guitar. The tension had finally just snapped the headstock right off. Not only did he have the wrong strings he likes it tuned to E so that just made it worse. The right strings matter, these guys had the right strings for a guitarron tuned to E.