I'll bet there are as many catastrophic engine failures as drum explosions. How many here run a belly pan or a diaper? A rod thru the pan or block at speed can be pretty spooky. Yet it seems many focus on the trans as a bigger safety issue. A good front drum and shield solves the problem. The stock front drum is powdered metal construction. It will spin beyond its design limit if the rear drum is not being held stationary. What holds the rear drum? The roller clutch, and in LBA applications the rear band. When the transmission output shaft is unloaded by excessive tire spin or drivetrain failure it unloads the roller clutch. The roller clutch can fail due to the unloaded condition. Now the front drum can spin to engine rpm x rear gear ratio (2.28). Say the unloaded engine revs to 6000 rpm (or higher). That puts the drum to a minimum of 13,680 rpm. At this speed it can disintegrate. A stock loaded front drum weighs close to 7 lbs. That's a lot of weight slinging around. Personally never had a failure. Seen a few live though. But I've seen even more hit the wall with engine oil or coolant under the tires. In fact I've witnessed more crashes due to chassis failure than the number of trans explosions.
Doug