Your vibration is probably not the actual gears. The gears are making everything turn faster, so a vibration that you might not have felt until 125mph now shows itself at the 110mph since it's all spinning the same. As for the converter, that does seem a little loose, but I have a 265mm 1a 2600-2800 circle D. From a stop it barely feels anymore loose than a stock one, and I'm on 3.42 gears still. With 4.11, it would seem like your 2b wouldn't take that much more to get moving but I could be wrong. As mentioned, I would make sure I had total confidence in my tuner to use him.