I would say No. The AISC 13th Ed. has some (not too many, but some) significant changes, even from the 3rd Ed. LRFD. As far as connections go, you are allowed something like 50% greater weld strength for welds loaded perpendicular to the length of the weld. This might affect your weld sizes significantly (causing them to be smaller than would be required by the 3rd Ed LRFD).