I agree 100%. I have been saying that for two years now and everyone here seemed to disagree with me. I put my kit together around the BellTech front coils as that was as low as I wanted to go. I used JLP shackles and set them at the lowest setting.... got 2 7/8" drop in the rear. The was left, and looks like a full Bell Tech kit without the annoying rear sag.

 

The emphasis was so that you would adjust your thinking about the relationships in the front suspension, not that you were startlingly dumb or anything.

I have done springs and arms. I still can't figure it out. I got well over a 2" drop with the arms, yet DJY says that he got only 1". How is this possible? A 2" lower spring pocket means 2" lower PERIOD. Right?

Well, I then installed a one inch spacer to bring the front end back up. It did not raise the height one inch -- much less.

The problem with figuring this stuff out without actually installing it first is that there is some geometry going on here. The springs attach to the control arms at a midpoint on the arms. So raise the spring an inch, and you raise the truck more than an inch -- right? In my case, it lowered it less than an inch. In DJY's case, lowering the spring 2" lowered the truck only 1" (note that he is using WC arms, but I am using DJMs, which are both advertised at 2").

I suppose the only way to know for sure is to replicate someone's known configuration. I am finally replacing the Hotchkis springs with Ruslows today. Since the Ruslows with the stock spacers are supposed to be about stock height, and the DJM arms drop my truck more than 2", I am hoping that the gods will reward me with about a 2.5" drop in the front. Any more that that, and the ground clearance suffers (and I am not able to get the camber back in specs with the drop I have have now).

In short, be prepared to experiment. The calculator appears to be of limited value here.