Exploding Torqueflight

Mad Dart said
Billet front drum and a bolt in Roller Sprag would stop this from happening.

Yep.

crackedback said
This is a 727 issue. Billet front drum takes care of the issue in almost every case.

904's don't do this unless you can twist your engine in the 10K range.

Hope the OP heals up quickly.

And yep.
The 904 has a much smaller diameter drum , so it is less prone to grenade if the sprag is over run.
Every time I see a picture of this , I wince and wiggle my toes.
Best of luck on the mending process.