That was behind a stock 350 TBI in a 4wd K5. That one went out while using 35" tires. I have another friend that had the same thing happen while pulling out of his driveway on 33" tires.
The problem with gov-locks is that they lock based on differential wheel speed. One tire has to get going about 100rpm faster then the other tire is going and then it will lock up (with a jerk and a bang). It is that shock loading that makes them go boom.
A much better diff to use is the 28-spline torsen's out of late moddle f-bodies. You used to be able to buy them from SLP (I think) as take out units for $99...but I think they dried up their supply.
What will it be in and what will you use it for?
Sorry to burst your bubble...but better now then when your's looks like that.