[BR3W CITY]

THe 246 is a computer controlled multiplate diff, and its also a 2speed. I've heard crazy good things about their speed of activiation and how crazy precise they are. The multiplates can kinda act like a viscous but from what I understand, handle more power since the level of "drag" cant be contolled with the computer. I think you can also mess with the allowed rates of difference, so like only allow axle rpms of difference (don't quote me on that last part, I was reading into it myself)

As for the 149 failing, I've seen a few threads on yellowbullet and a handful more on the TBSS and Silverado SS forums. Guys bust the chains, which sometimes damages the case. The biggest problem seems to be that the 4l80e output conversion ends up failing.

A guy on pirate4x4 mentioned some concerns with heavy large diameter whees (speciafically offroad stuff, but the weight of big rims would apply the same). The jist of it was that the heavy rotational mass and large diameter can mean a ton of heat and problems with the differential speed at each axle. The large wheels change the way it reacts to the torque biasing, because they have a different # of rpms. I'm probably not exlpaining it that well.