timing questions for '68 318

hi, i have a novice question. my timing marks on my cam sprocket and crank sprocket are lined up but my timing mark on the harmonic balancer not at 0 at TDC for the #1 piston. what am i doing wrong? there only one way for all of these to line up right? the #1 piston is the drivers side front piston right? what the %*^&*!