The cam gear has either abcd or 1234 stamped around the gear. There is an arrow in the top of the plate behind the gear. Align either the A or the 1 at the arrow. Make sure the number 1 piston is at TDC. Install timing belt and set tension. Rotate crankshaft by hand 2 revolutions to make sure timing marks are correct. The cam shaft sensor has a dot mark on the gear and the shaft. Align the marks together and install into head with the dot at the installation hole. Do not use the roll pin as a mark.