Front springs & Steering Issues

[Nukes16]

Hey guys, once again I'm trying to get to the root of my steering problems. I am having the same issues as before and it seems that nothing I do makes any difference. It still won't return to center after I turn, and it is stiff under load. I have replaced the steering column, the pitman arm, the idler arm, the ball joints (twice now), I have checked the spindles for tightness... again, but still no changes in my steering. I have had it aligned twice and it is on spec. The only thing that I am wondering is if the springs are too soft. I have noticed that it has an excess of travel when I jack it up, it really sags low. I put in 2.5" dropped spindles and 2" dropped coils but I'm not sure about the history of the coils.
Is it possible that the coils are too soft and allowing the truck to sag too much and therefor it is causing my spindles to "bind" on the ball joints making my steering jerky?
This is all that I can think of at this point, looks like I'll be taking it apart again this weekend?
Any suggestions???

Thanks in advance.