Thank you for sharing this. I noticed a slight crack on one side prior to my body ('65 Barracuda) going into the paint shop, now I'm concerned about this reoccurring. I did some research on frame connectors and see that USCarTools makes them. I never gave body flex a thought until I read your post, I'm ordering the frame connectors, I'd hate to see these cracks come back after the car is painted. Edit: Found some "before" pictures, its all filled now. I seem to remember the joints had lead in them.
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