do you get the "wander" condition only when hitting a bump ?
could be "bump steer".
i see you have a dropped front axle.
your drag link needs to be parallel to the frame.
i have a 3 inch dropped axle and 1 leaf removed in my 57, with original steering box and leaf spring bushings, and it runs perfect at 80mph.
a few other guys will chime in here before too long also.
leonard
