What kind of performance gain did you get? I just took apart my TAV2 for the new engine and the gears look real pointy. I'm guessing thats a sign of wear.
Its good that theyre pointy. When theyre dull and rounded it means that its wearing out. And yes... I had a 9t on with my lightly modded 7hp subaru and it shredded it in a month. Buy spares if you gear it high and have a big motor! They wont last long!