I bought this one years ago for $50 at a swapmeet. As yet I've been unable to determine who made it. It didn't look like it had ever been used. It goes on the stock pins and then you adjust gear clearance. The idler is on the right side as opposed to most others being on the left (should that matter?). It has timing marks on the gears but they're kind of useless because the idler is not the same size as the bottom gear so as soon as the motor is turned over once, the marks won't line up again for God knows how many more turns! What I need to know is how much clearance the gears need and how you get that (I've heard you run a piece of paper though each gear and that's the clearance - about .006")