Have you done shocks? Swaybar links. That would be my starting point. you have done the other stuff.

 

Ironically I did shocks the night before last. I knew they needed to be replaced and figured if it was the cause I would kill two birds with four shocks (lame joke)

So last night I decided to replace the lower ball joint because I put a stethescope (sp?) on it while my wife turned the wheel and it sounded the loudest when I put the stethescope on the lower ball joint.

As I was taking the axle nut off for some odd reason I noticed the lower (rear) caliper hole looked odd. Take a look at the pic and you'll see what I mean. It was ovaled towards the back of it. I must not have tightened it enough when I did my headers a while ago, which I don't doubt because I remember when I put them back on my old school torque wrench with the needle, I went to torque it and couldn't read the dial very well since it was facing the inside of the wheel well.

Only question is was it the caliper mounting hole or was it the ball joint? I say this because I was halfway to getting everything apart when I noticed the caliper hole. So I replaced the lower ball joint just in case. I'll say it was the mounting hole because it creeked the most when I turned left and the ball joint was in great shape (no movement in the tire before I started)

To fix the problem with the out of shape hole I used a step drill to taper each side of the hole big enough (about 1/16th") to let a brass washer I flared fit snuggly once I tightened up the caliper mounting bolts.

Either way (after a short prayer) I took it out for a ride and now all I can here is the sweet sound of my headered cherry bombs

Thanks everyone for reading and offering advice. Honestly it was the emails I was getting on my blackberry that kept the problem on the top of my list.

 

Glad you got it fixed. Thanks for posting the fix.