I recommend that you install either 5 or 6 degree caster shims between the front axle and the leaf springs. Using the original castor shims with your power steering setup will give you no feel of the road in terms of going straight down the road. You will also lack the automatic return to straight ahead coming out of a turn. I do not know why this is. I, and others have found that it is just what occurs, and more caster angle fixes it very nicely!
Carl

1952 5-window - return to "as built" condition | 1950 3100 with a 235 and a T-5 transmission