Center link swap

You can use driver p/s tie rods on manual but can't use manual on p/s car.

Try this first.  Have an alignment shop put 3.5 degrees positive caster in it. That will probably fix your issue.  Factory spec is zero caster, so 3.5 will make it go straighter and it will have more resistance to turning.

These are my settings before the 2021 Bash.

Arning/Shelby relocation 1”
Offset upper control arm shafts (respectively per side for caster gain)

With these mods, my factory power steering is good at interstate speeds too.

Are your ball joints in good condition?
Or at least verify.

I had ball joints in past that failed/worn and my steering was terrible.
Top on one side and bottom on opposite side.
It sat too long and/or lesser quality parts back in the day.

TKOPerformance wrote:

You may not be able to get 3.5 degrees positive caster on a factory system.  I would advise doing the Shelby/Arning drop first, because that will also get you positive caster by moving the UCA about 1/8" rearward in addition to lowering it 1".  You'll need 3.5 degree positive caster for the Borgesson system to return to center properly anyway, so might as well address it now. 

It has the Shelby drop already.