i have run them as much as 150 passes. a friend broke one in his BBC, 330 passes.

BUT rods don't usually just break, the bearing goes first, then this makes the rod break. SO usually you looking for distortion on the big end of the rod. Most people have their own ritual based on ?? they replace them at X number of runs or...just roll the dice. I know a lot of people that say, " fix it when it breaks" LOL
You do see some using them in bracket motors and they run them 3-400 passes a season.

Its like "how many licks to the center of a tootsie pop".....LMAO !