Well I knew I was pushing the cast crank too hard but it kept passing magnaflux during inspections so I was trying to get one more season out of it before I changed it out. As you can see that was a big mistake on my part. IMO with care they live well at 7200rpm but they don't like 7500rpm. I will say that whirlaways make for very nice shut downs and recommend them for everybody.
Here's the link to my photobucket if you're interested in all the carnage pictures
Carnage 7_2_2011 pictures by carnivalride - Photobucket