Exploding Torqueflight

The rules are because it happens to certain transmissions and they are too lazy to write rules and inspect cars to determine who needs what. It's easier to "blanket" statement the rule even if it's not needed on some stuff.

A stock 904 front drum takes ~ 24,000+ RPM to reach critical mass. That's about 10K engine RPM in 2.45 low gear transmission.

I've never seen a 904 front drum explode in 40 years of being around this stuff. That said, it's not a bad thing to add protection, even if it's 'peace of mind' stuff.