You need feeler gauges and pin type feeler gauges. You need to check the distance from the end of your starter pinion to flywheel and the distance from the tip of your starter tooth to the flywheel indention. If those are both dialed in correctly, your starter will work flawlessly unless you have chewed up your flywheel teeth. I have to run but there are specs for both measurments. If you starter is to close to your flywheel, it nose must be shimmed as shown below. My advice is to find both specs and make sure they are within tolerance. I bet they aren't.
