When they hunt like that something is moving.

I bought a set of SS springs (way back in the day) off a dude with the hangers and everything. Just bolted them in. After damn near getting the tree, the left guardrail, back over the center line, back to the left guardrail, back across the center line and almost into the door of the dude in the right lane I lifted.

25 different pit heros tried to tell me the front end was jacked up, but I kept telling them every time I shifted or lifted it changed directions. I spent a considerrable amount of money on the front end but still, you NEVER knew which way you were going.

I caught it by plumb bobbing off the axle faces and measuring to find that the axle was not square in the car. I started taking stuff apart and that's when I found out the dude used bolts that were too small in diameter throught the front spring eye! So literally, every time you changed load (shifted, lifted, braked etc) the axle could move front to rear in the car. Sometimes the wheel base would be longer on the right and shorter on the left, or it could be shorter on the right and longer on the left.

I ran into the dude several years later and he told me that's why he sold them.

So any time they move around like that I look to the rear end.