Steering ratio doubler advice.
Have you driven your car with manual steering? A-bodies in my opinion don't need power steering. My go-to manual steering is the 20:1. It's one full turn faster than the 24:1 but not as "heavy" feeling as the 16:1. Electric power steering? Why? Are you planning to upgrade your electrical system at the same time? Keep it simple. These cars in nearly stock form with new suspension and steering parts are great performing cars. Add heavier torsion bars, good performance shocks and sway bar to make it drive more modern.
Have
you driven an A-body with 16:1 manual steering and 275mm wide tires in the front with a good amount of positive caster? Because that’s exactly what I’ve been doing for the last 10 years with my Duster, using it as a daily driver with 1.12” torsion bars, Hotchkis shocks, Hellwig sway bars, etc. I’m well aware of how it steers and handles.
20:1 is still too lazy a ratio for AutoX IMO, you’d be sawing away at that steering wheel on a tighter course. 16:1 is good, but with wide, sticky tires on the front and good alignment settings the steering effort in tighter courses gets pretty high.
The Hotchkis Challenger, while a larger Ebody, had great success on AutoX courses using the 12:1 ratio power steering. Although an early A may be significantly lighter, the 67-76 A’s are not ridiculously lighter than an E.
EPAS is a great way to add a power assist, most are available with potentiometers so that you can adjust the amount of assist with the turn of a knob. You’re already driving an alternator, and depending on your engine, radiator, fan and accessories adding the additional belts and pulleys for standard power steering can be a significant headache. Plus the EPAS will be lighter- no power steering pump, no heavy power steering box, no hydraulic lines. Just an alternator you already have to run and the EPAS itself.
Not sure about the OP’s car, but I have a completely new American Autowire harness and a 160A alternator. So EPAS is a no-brainer for power assist steering. And I could dial it up for AutoX and then dial it back down for the highway.