Thanks for the tips Mustrum. Mind if I ask what your setup is and what kinda track you run on? I run on an outdoor dirt/clay track that is goes from low-grip (in winter), to medium/medium-high in summer when it warms up and dries out a bit. It's a good mix of high-speed sweepers flanking a straight, and a tighter middle section with some elevation changes that you need good drive out of rather than always high corner speed. I'm going with the starting gearing mentioned for the D413 - 34 pinion on a 13.5 motor, and I'm going 60wt up front and 40 in the back using XTR shock oil. Will see how that goes.