What causes truck lean/tilt

[NicoSlam]

So I did a 5/7 drop on my 69SWB the front RT leans about 5/8" in comparison to the left front. I have dismanteled and confirmed that the 2" spring is sitting both on the top and bottom pockets but still looks bad. I had the truck aligned and they did not notice anything out of what. Actually they were able to get it pretty close to nominal with a couple of shims. Ball joints were replaced as well. I took multiple measurements to try and identify the issue but the only difference I noticed was the space between upper and lower control arms when compared from LH to RH. Is it posible that I got a wrong spring from ECE. I called them this morning and they suggested that I swap springs to see if the issue moves from RH to LH but I really dont want to completely take the truck apart again unless I have to. Is there a key measurement that can help identify the issue? Can someone suggest where and what to look for?

thanks