Steering All Over the Place at 55mph+
The one in my 67 was VERY VERY bad, but the present issue is that they are hard to get (one year) and VERY expensive
Exactly. This is the one problem. When they do wear they are a one year only part.
I went through about 3 in the many years I autocrossed (with sticky tires) using the '67 K-frame in my '67.
I know people who autocross with the earlier cars too, and plenty of people rallied those early cars. So I agree its a weaker design but no more of hazzard than any other part in the steering.
THE PROBLEM... since I've had it I've basically kept it under 55mph. I did notice if I do a sudden lane change it feels like I'm going to lose control. If you wobble the steering a wheel roughly a 1/4" either way it's pretty non-responsive.
Approach it this way.
1. Is it related to the alignment? Toe out will cause a darting response. Get a shop manual. The front suspension chapter explanations are excellent. The procedure for setting alignment remains the same. Hieght, Camber, Caster, recheck camber, Toe. All four must be done, done in that order and done at ride height. The specs can be adjusted as mentioned earlier as high crowned roads and bias ply tires are no longer in play (for the most part).
2. Is something loose?
The play in the steering wheel is within the norms, although it shouldn't really be noticable while driving.
The first thing to check is the wheel bearings. Normally I'd say check the front, but as the car is new to you, check the rear axle play as well.
- check the front wheel bearing play by holding the tire at 12 and 6 o'clock.
Next check for steering play. have someone turn the steering wheel while you observe under the hood. Then jack one wheel at a time up in the air and work the week while watching the linkage. Do not go underneath without a jackstand! You're just looking for any connection that shows looseness. Then do the other side. Observe each portion of the linkage, tire rod ends, idler, pitman, to see if they all move perfectly together and no up down play either.
Then do the ball joint and control arm checks as the shop manual explains.
Can this be from the wider front wheelbase?
All RWD Chryslers have wider front wheel track than rear.