Coil Over vs Torsion Bar

Ask @GMachineDartGT He runs torsion bars and connectors and go knows what iother stiffners and he had chassis cracks that he fixed recently. He had the pics posted on Facebook a while back not sure if he posts them here or not.

So apparently even that great stock engineering cracks the chassis.
I'd say that would have as much to do with the car being 45 years old as anything.