The resolution is at 350 on that one but it should be 300. So if you're using Photoshop, go to Image then Image Size and change Resolution to 300. When you do this the Pixel Dimensions and Document Size will change so just change Pixel Width back to 3260 and Height to 1370 and it should print the perfect size.
Just noticed you said you open in Preview and print @99% so 300/350 is 85% try that and see if it fits.