Hurt the 904 and 8.75 at the same time

If you can blow up an uncompromised front drum in a 904, you are spinning some BIG RPM. That is a 727/sprag problem.

If you think something is wrong, tear it down. Seen 904s run for a while with the sprag toasted. Is it smart... probably not. Fix it once. No need for fancy stuff there on a 904.

TF trans is simple to rebuild. Plenty of YT videos and guides. If you can build an engine, you can do a TF trans. Isn't any black magic in these things.