Launches right, dives left

[ragtopfury]

Took the Shelby Dakota on its maiden voyage before turkey dinner on Thursday. Never felt this issue before in any vehicle I've had.
Wants to pull right upon acceleration and dive left upon letting off the gas, no braking involved. The dive left is more pronounced than the pull to the right.
When braking, hard or easy/normal, stops true and straight.
The only suspension work that was done for the rebirth, was adding a 2 inch lowering block to the rear so the truck sits level. I've gone back over the ubolts and blocks - everything is tight, centered and where it should be.
Would an altered pinion angle cause this?
Ideas?

 

[67Dart273]

Check the rear suspension/ axle for "square" to the frame/ front tires

Is it possible the lowering blocks are AFU? AKA spring center bolts are not engaged, holes not square, etc?

 

[Mr. Sinister]

Worn out leaf spring bushings?

 

[ragtopfury]

I think you nailed it Del.... center to center on the right side wheels 112" center to center on the left side is 111.5"
Looks like the left side is misaligned, as the wheelbase is supposed to be 112"

 

[ragtopfury]

Follow up for any who might care, or not. LOL
So I got it right on Tuesday. Took the lowering block off the left side and it will mover a half inch fore/aft in the centering bolt that holds the spring pack together. Took the right side out and it does not move. So made a shim to fill the gap in the too big hole, bolted it all back together and I have 112" center to center on both sides to the front wheels. Went for a quick drive and all is good.