I’ve experienced Studebaker Avantis and early Avanti ll’s (all with p/s) having less steering effort than the later Avanti ll’s (through ‘85)
All power steering components are the same between these cars EXCEPT the steering box itself, which was changed out when the supply of Ross boxes ran out.
Some say the replacement steering box was originally made for a fork lift … I do not know if that’s true or not.
But a change in ratio between the two units could have an effect on steering effort.
I can say steering effort in my ‘63 Avanti is definitely less than in my ‘83 Avanti.
PS…. It occurred to me that a change was also made in the power steering pump itself, going from the Eaton style to the GM style… If there was less pressure produced by the GM pump, I suppose that could account for additional steering effort.