I'm trying to fit this GoodYear timing belt on this engine, but for some reason I can't for the life of my get the back plates and sprockets+belt marks to line up. They're about a tooth off. I read the tutorial and it says just worry about the sprocket and belt marks, but why on earth would the back plates marks be inaccurate? It's supposed to be the tooth count mark...luckily there's info on that already...otherwise I'd have no idea what the actual timing component relationship would be since the marks are inaccurate. I'd have to try spinning the crank a ton of times for trial and error...