My wife has a 70 4 door satellite that that has started wandering all over the road. I replaced the pitman arm and idler arm .as they had a lot of play, thinkig that would cure it. The tie rod ends seem fine and the balljoints o not seem to have any play. It could probably use new control arm bushings , but I would not expect it to wander as bad as it does. Any thing over 40 mph is terrible. I am limited on time until winter, so I would like to hold off on a complete suspension rebuild until then.
I don't know if it matters, but it is power steering. It has a 3g hemi I built with the hemi ps pump powering the stock ps gearbox.
What should I look for next?

Loose lug nuts?

Bent wheel?

Broken belt or belts in a tire?

How much play in the steering box? (How much can you turn the wheel without the front wheel moving?)

Bad tire can do it. Measure the toe. If car is toe out it will wander like you are saying.

Did you get the front end aligned after the swap?

I did not get the car aligned. just started doing it. Rims not bent, air in the tires., wheel bearings good. Will check the toe in and tires this weekend. Thanks for the suggestions. I would like to figure this out!

I will check the play in the steering box. It was fine and just started doing it. We do live in the land of potholes though.

Does it wander, or are you over correcting it?
I believe the pump pressure the G3 Hemi puts out is quite a bit higher the the pressure the old pump put out. That would create a very sensitive steering and over correction might make it seem like it was wandering. My son ran into this when he installed a 5,7 into his 57 Wagon, but I don't remember what we did.
There are a few options for reducing the pressure output of the steering pump. Google is your friend on this one. Gene

Poorboy, It really seems to have a mind of its own as to where it wants to go. The hemi has been in the car about three years and has been fine until now. I had rea about the pump issues when I was doing the swap, but until now have had no problems. Maybe the suspension is now worn enough to cause what you are saying? I just rebuilt the suspension on my son;s valiant this spring and my knees are still hurting from it! I guess I should have went through everything on the car while the motor was out, but the wife had to quit her job because of her back, and anything hemi is expensive!

I've seen old strut rod bushings deteriorate to nothing and cause this.

ONCE, a VERY long time ago I came across a '65 Belvedere with loose steering box bolts.

Robert

Have your wife/someone get in the drivers seat and wiggle the wheel form side to side and you look under the front end at the steering/front end parts and see where the play is........replace parts w play....done.

That is how I found the worn pitman and idler arms. I will have one of my sons get under it this weekend while I move the wheel. Maybe I'm just not seeing the problem.

Doesn't take much movement in front end parts to create a wander.
If the power steering setup was working OK before and now it wanders, the steering pump pressure is probably not your problem, that would have been an issue when the Hemi was installed. Gene

Check the bolts holding the steering box in. I had them loosen up in a 68 Roadrunner and it was all over the Road. You could not see it unless you were watching while someone was turning wheel lock to lock.

I think the suggestions of bad tire are good ones, since nothing else seems to be the issue so far, although the few I've had usually cause a pull. Bad strut or shock in older car would definitely cause this.