That cross section is good metal; the crack cause water ingression, that started working on it.
Rust applies a lot of force as it grows.
That's what good metal looks like, broken. Small grain boundaries, and no 'elastic deformation".
If it stretches like taffy, that's when you know the metal is crap.
I'd bet you couldn't break one of those with a sledgehammer, personally.
I have an old one; when it gets warm this year, I'll give it a shot.
Red '96 Cougar XR-7 240k mi. '02 4R70W, PST DS : '03 PI engine, 04 maf, 24lb injectors, 2.5" exhaust, '02 4r70w + Jmod, DirtyD0g TC + cooler + 3/8" lines, 255 walbro fp. Alpine system.
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Black '97 Tbird Limited Edition, '02 4R70W, 255 walbro, PST DS, PBR Brakes&SS lines, Toicko Blues & Springs, GrogTune.
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