catastrophic failure

[mn box s]

One thing that has not been mentioned... Journal bearings if you spin a bearing (2 "C" shaped metal pieces that float between the rod and crank). These damn things are known to slide under each other which will cause the throw to be longer in both directions. Your rod may look fine or even be fine so just double check to see if this has happened. Common fix for this as follows: new custom bearings to be machined, crank machining, new rod, head to be decked and new piston. I read the bottom was fine, I'm just saying take another look for this if it has not been done. You described this problem.