Not much possibility, as far as I know. The self centering/castor angle is dependent of the kingpin inclination angle, as I suppose you know. I cannot see how you could change this without indulging in some major surgery. So I think it is inherent in the Morgan design. But strange as it sounds, my car is much more self-centering after I fitted PAS. I cannot explain why, there should be no power centering the wheels. But that is how it is. Of course, fitting PAS IS major surgery....
