I'm converting the wifegod's 71 R/T Challenger from manual to power steering.
I picked up a new Mopar universal steering coupler from Flaming River which I hope to use with the new PS setup.

I'm researching the companies the sell upgraded rebuilt power steering gear boxes like Firm Feel, Steer and Gear, etc.

In talking to one vendor I was told I can't use the Flaming River coupler with a Mopar power steering box as the box's input gear has to flex in and out with the different power steering fluid pressures and the FR coupler is solid and won't flex?
He told me this isn't an issue with the manual steering boxes.

I called Flaming river and their confused tech guy wasn't much help.

Anyone have any information or experience?

Thanks in advance.