[nickair]

Hi Mark.

This is a wonderful site. Great info on most everything. Great people.

Your steering:
First you may want to try tightening your Pittman arm at the steering box shaft. Easy and free to do. Also the steering frame mounting bolts. Tightening just one castle nut position and re-cotter pining these nuts can take up to two inches of steering play out. Been there, done that. Not saying it will help with your shimmy. I am not an expert, although many on this site are very knowledgeable and helpful.