1970 Duster power steering issue

Over 20 years ago,I pirated the complete system from a 70 Duster340,and installed it on my 68Barracuda. I agree it was over-boosted, but it steered very well; even with a small fat-rimmed steering wheel. I reduced the sensitivity and the lowered the pressure, and now it's even better.
But the old man is right, the p/s boxes are ratio'd about 50% faster; 16:1 versus 24:1 for the manuals.
Don't bother with pulley sizes, the pressure is controlled by a hi-pressure relief valve on the back of the pump.