Dave,
You are absolutely correct about increasing caster in the front suspension of a Pantera. Drive one with 4 to 6 degrees of positive caster will make you a believer, especially if you have wider front rims and tires. Yea, steering effort is increased, especially when parking, but power steering is not a necessity. This caster thing has to be one best kept secrets from Pantera owners. It's probably so because the front upper "A" arms must be modified to get more upper ball joint position movement, which translates into more positive caster above 2 degrees, regardless of how "good" your alignment guy is.