If I got a 2 series carrier how could I run 3.73 gears in it. Do I have to get the specially made gears, or can I use a spacer. Also, if I could use a spacer, do I need anything for the pinion gear (spacer, shim, ?).
Thank you,
Kyle

There isn't a thick 3.73 for the 2 series differential. You will have to use a spacer, which I don't recommend. Using a 3 series differential is the best thing to do. As for the pinion, it will have to be shimmed just like any other ring & pinion installation. You will have to set the pinion depth, bearing preload, backlash and contact pattern.