The firing order is usually cast into the intake. I don't mean to insult your knowledge, but for the SBC, the number one cylinder is the left front and # 2 is right front, with odd numbers on the left side and even numbers on the right side. The normal procedure is to turn the motor until compression just starts on the number one cylinderand then turn the motor to line up the timing marks (should be very close). Now you stick your distributor so the rotor tip is pointing at the # 1 cylinder. Then you can replace your rotor cap and insert the wires IAW the firing order, going clock wise from # 1 which will be nearly in line with the # 1 cylinder.