sounds like you have a bent rear sway bar or ,the sway bar links are not Adjusted correctly. I have5 3/4 on the left and 6 inches on the right. you could also have a worn bushing somewhere on one of the rear links. (letting one wheel drive forward when you get on it hard) does it also try to move around when you let off the gas from a hard pull.?

I have all my rear suspension links replaced with Rudy's adjust the links ,I have centered my rear wheels, along with getting the distance between the front wheel and the rear wheel dead on the money. I do have the KW's on my car but I had to adjust them 10 to 15 times and may still need to adjust some more,

you cannot use the pullovers around the shock for the crossfire, Because the shock support is not strong enough, you'll push the shock in the spring right into the trunk, of course you could well plate that would go down to the frame up above the shock support and back to the frame, that might work.jim