Anyone running a 904 behind a 340?

Duane said

Totally agree. Bolt in is better, but the better sprags also increase the roller count as well.
My point was on any torqueflite it is a common practice to upgrade the roller clutch.
The 904, because it is riveted into the case,
Was a better design, but there is now an upgrade as well for the 904.

Click to expand...

I hate to tell you this, but it's not as common upgrade as you might think. Most of the bolt in sprags are just stock ones which have been drilled and tapped. They have same element count. They may not turn in the housing , but the gut's will fall out, which is usually what happens when they fail, just like a stock one.
The extra element count sprags are more robust, but will still fail if abused. They are not a problem solver solution.