I need to get my car ready for the local 1/8 mile drags in 5 weeks and will be installing a 4.11 and new 3" axle shafts with spicer u-joints in the next few weeks.. Here is the current problem and I will try and be detailed so hopefully I can narrow it down and make any needed repairs while I have the rear end apart..

When I hit the brakes, the car wants jump to the left.. At high speeds, on an uneven road, when I hit the brakes, the car pulls and wonders bad and I almost lost it during my last 100mph run on a rural back road doing a test run... It doesn't seem to be bad at high speeds if I let off the gas and coast to a slower speed but when I start to apply the brakes it gets really lose... Also, when I launch the car from a standstill, occasionally, but not always, the car will jump hard to the left.. It almost feels the front tires leave the ground and its torqing to the left but I cant tell if its the front or rear that's jumping.. At first I thought I had a sticky caliper but now I'm starting to think its in the rear? I just had a front end alignment and everything looks good and it did this before the front end alignment too.. I jacked up the front and rear end and applied the brakes and all 4 corners seem to be working with no sticking at all.. While the rear was off the ground I tried to find some play, including side-to-side but everything seemed to be pretty tight but that doesn't simulate 450ft lbs of torque either

Thanks for any hep!!

 

Trailing arm bushings?

 

Thats what I was thinking too but its amazing how it can feel so much like its in the front end..