83 C30 rear axle alignment

[CKluttz]

1983 C30. In the process of lowering the truck, front was lowerd with drop A arms, and rear with new hangers, shackles, and removing the helper leaf spring. Ran into a problem with the rear axle alignment after everything was installed. The driver rear tire is pushed forward 1/4 inch compared to the right rear tire. We have measured it from several different refrence points... The leaf springs were removed 1 at a time, new bushings installed, and the helper spring was removed. Then reinstalled. I have checked to be sure the spring bolt is in the spring pad locating hole... I also used new U bolts. The U bolts are the correct square type that came off the truck. Only diffrence, is the orginal U bolts were flat where they sat in the top plate unlike the new which is round.. Any ideas of why the left would be shifted forward.. or is there any reason to be worried?