Nails for deck framing
Those are not the correct nails, period.

A "Box" nail is thinner than a "Common" nail, and unsuitable for framing.

Per chart found here, 0.162" .vs. 0.135" which is 144% more steel in the common nail (review geometry if you don't get that.)

Box nails, being thinner, are easier to bend, as well; but predrilling can help if you are not a skilled framer - however, the fact remains that box nails are not suitable framing nails. You may find pre-drilling the 2x8 for 16d common galvanized nails to be beneficial, depending on your hammer skills.