John,
My little modified street roadster has side arm steering, Schroder midget steering box, and if the alignment was perfect it goes down the road pretty well, and only a big one wheel bump would set it off on the "death wobble". When I installed the Howe 2:1 speed increaser backward to slow the steering down I also installed a steering dampner, which I got from So. Cal. and that was the best thing I have done to make the steering stable. I connected it between the spring mounting bolts and the cross link it works great!
If you don't go with a dampner make sure that all of the steering parts are stout and all of the joints are tight. Normally what will happen is if you go into a "death wobble" as you go faster it will go away because of the gyro-scope action of the tires. The larger the diameter the quicker it goes away. Also remember that it will add some steering resistance, if I had not slowed the steering down with the Howe unit I don't think that the dampener would be a good idea because of the increased steering force required.
Rex