Replacing Hard Brake Lines w/ Stainless Braided

[RKHiPerformance]

I'm installing a set of Baer discs on the rear of my '84 Monte SS.
Is it okay to replace the factory hard lines that run from the junction at the center section to each caliper with flexible stainless hose, like the Russell teflon-lined stuff?
Do these braided lines flex too much?

Thanks,
Rick