It is not usual to take the adult body size into account when flushing, although the group has recommended it for children because they are more sensitive. The predominated factor is your metabolism which is not linked necessarily to size. The Hulda Clark
flush is quite moderate using 4 fluid ounces
of each but there is nothing stopping you moving into a more comfortable zone and trying 3 fluid ounces
of each on your first flush but the results can not be guaranteed, however, they can't be predicted anyway.
I think that it is most important to make a start and go from there.