TorqueFlite 727 904 Cut Bellhousing for Converter Bolt Access

You both didn't get it. Chevy bellhousings don't crack under normal use because they have a cast in flange.
And according to multiple people in this thread who have utilized the notch modification for their specific 727/904 applications, the bellhousings don't crack and converter seals don't get destroyed from grit, especially if they built a cover for the notch.