Those #'s (3 6 9 0) are positions to adjust your secondary spring preload (wrap) There is a chart on the tech page on all of these adjustments to get your desired preload. It is called wrap because it is also a torsional spring, therefore twisting it in a certain direction will adjust the preload of the spring. The numbers 3,6,9,0 appear on both sheaves of the secondary. The helix angle's are
8BV90: ?? you sure that isn't a typo? 8BV91 is 39* helix... if that is for sure the # then i can't be any help.
8BV31: 43*