The Horrible Mustang Lean....

Before any other messing around, measure the ride height to the top of the fender wheel well openings, or even better, to points on the frame on both sides so you have some numbers to go on.

Then you can see if messing with the springs, or say, adding new spring isolators on the low side would fix it.

There are a number of ways to deal with this, and these bodies are more flexible than you would think.

Airbags can also help.

This sounds like a subject that shouldn't be abandoned just yet. Same iss ue with the Stang I just picked up, it leans to one side. Iknow that the bodies can twist easily on these things, but the one I picked up had one female driver that babied the thing. It doesn't fit the profile of a car that's been pounded on. It's bone stock and has some really old suspension equipment on it. How would one tell if this problem is suspension or body-flex related? Perhaps this should be addressed, it just makes the cars look saggy.

I broke a small piece off the left front spring and my car sat funny, my C springs fixed it. Make sure, as others have said, that the front springs sit in the perches correctly.