I would think that the OEM shackles would be way more sturdy than what you have. Short of heating them or using a lot of leverage I have never seen a bent set. Something is wrong in the geometry of your axle set up.🛠

Martin
'62 Chevy C-10 Stepside Shortbed (Restomod in progress)
'47 Chevy 3100 5 Window (long term project)
‘65 Chevy Biscayne (Emily)
‘39 Dodge Business Coupe (Clarence)
“I fought the law and the law won" now I are a retired one!
Support those brave men/women who stand the "Thin Blue Line"! Hug a cop!
USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)