If you go to the subscriber's section of View Camera magazine you will find some additional information about how to match dichromate strength to negative density range specific for the Sullivan tissue. I plotted some curves for my article on carbon printing that was published in the Jan/Feb issue but they were omitted from the print publication. There was some difference in contrast between the various B&S tissues that I tested but the generic information should be useful.
Of course, to obtain the same results you will have to follow my conditions not only in terms of sensitizer strength but also as regards length of sensitizing, method of agitation, type of squeegeeing used after sensitizing, method of drying, and length of time between drying and exposing of the tissue. For good results you really need to be consistent with technique.
Thanks Sandy, I'll check that information out now.