Bending a sway bar
No help on the rear bar, but how did you mount the E body front sway bar? I put one from a 70 Roadrunner, which is the same thing as an E body bar in my old 64 Belvedere wagon many moons ago. Used the factory Early B body k frame and just cut a notch in each side so I could pass the bar thru the k frame like it was on the Roadrunner. Drilled holes for the mounts to the bottom of the k frame just like the Roadrunner and used the lower control arms from the Roadrunner with the inner style sway bar tabs. Worked slicker'n cat poop on linoleum...lol.