I have had the same 904 in use since 1993, the only failure I have had was the rear drum separated...kind of hard to explain...but it was just a perfect break in the drum...you had to see it to believe it...

In fact at MATS, the tech guy asked my daughter about a shield since the dart runs low 11s, and said something to the fact about running a TF without a shield was dumb...I told him it was a 904 not a 727 and he was confused.

Tony

70 AARCuda Vitamin C
71 Dart Swinger 360 10.318 @ 128.22(10-04-14 Bakersfield)
71 Demon 360 10.666 @122.41 (01-29-17 @ Las Vegas)
71 Duster 408 (10.29 @ 127.86 3/16/19 Las Vegas)