Eagle Cast Stroker Crank- Problems or No Problems?

I have one to use with a W5 headed roller camed motor I believe that it will be at the edge but my theory is that the ones that are breaking have not been balanced correctly as they come INTERNALLY balanced from Eagle and people think cast crank use external balancer this is not that case with these cranks I had mine balanced by one of Australia's best and at this time we found that if fitted with External balancer over 200 grams of weight would have to be removed from the bob weights at each end and was only 85 with and Internal Balancer then we checked the catalog and low and behold in black and white was INTERNAL balance .
also there are a number of things that can cause a failure of parts and its not allways that part that caused it