Hello,
since "divided D-76" is not an original Kodak formulation there are several formulations circulating. A concentration of 60 g/ltr. is too much. I use 30 g/ltr. In photographic formulations under the name "borax" if not otherwise stated, always the "decahydrate" (with 10moles crystal water) is used. In the U.S. the company "20 mules team" makes borax.