My bow weight is currently sitting at about 61lbs, but i will be cranking it up to 70 in the next few months (my bow range is from 55-70).
Currently according to the chart they are a tad stiff, but as you said you are going to be cranking the bow down so they will fall in line with the extra draw weight.
If it was me I would not be rushing out to buy new arrows.
I prefer an arrow be a tad stiff then a tad weak in the spine.