ok,you gotta 50 50 change on getting it right.Line up the marks on the crank and the timing cover.Take the gear on the IP and find the Y marking.Count 19 teeth in each direction from that tooth marked with a Y.Mark said teeth with a paint pen.Now,take a straight edge and connect said dots with a line.Put the gear back in alone with the Y down and the line even with the front of the timing cover.This is not a fool proof method but it is easiest.There is a 50% chance that the gear is now 180 degrees off but that will only mean you need to light up the marks again,Pull the gear out taking note if the Y is on top or bottom this time.If it was on bottom then give the engine a full turn and line up the marks.Now put the gear back on like you did before using the line across the face.Pretty easy and you have a good chance on getting it right the first time.