Not sure if this will help, but I just setup my new Pantera - its a 60#'er but has the same cams. Anyway I didn't worry too much about what the manual said or what # it was set to - I just increased the drawlength until the valley felt right. I think it hit an inch or so before I was at my normal set point. (I used to build Greenland Kayaks, so I don't get too uptight about measurements...) Up until this point, the draw stop was set fairly far out, so I could continue to draw the string back farther than I liked - got as far as my ear before I gave up.
The next thing I did was to set the draw stop to a spot shorter than was comfortable - then gradually move it back until the wall hit right at my normal set point. My previous bow didn't have a draw stop, but the cams had a pretty solid back wall on their own, but not as nice as this.
Hope it helps,
BTW - just pulled my bow out - the drawlength is set to #3 and based on my arm span, my drawlength should be 29".