rear leafs 68 barracuda

does anyone on this beautiful planet know why my rear wheels are closer to the front of the wheelwell then the rar (not centered) i bought new heavy duty springs from mancini and two problems---1st....wheels nottt centered in the wheel well and second the rear seems to high and the kyb shocks i bought seem to be at the upper most travel and if i hit a bump are the shocks gonna break/pop out ??? lol---anyone ever seen these issues?? cant seem to find anyone with the answer...not even mancini!! are all a body leafs the same or are there specific leafs for the barracuda only??? thanks for anyones help in this here matta...merry christmas.