Old references from before the lead free introduction are not exactly correct now as lead free solder does not wick up/down the hole as well, so where you may have had a 1mm hole for a 0.8mm lead, now you would be better of having a 0.9mm hole.
It does make it just a little harder to insert components but the sodlering is much better.
it is all trial and error to see what is best for your assembly processes.