[CardinalStang]

Originally Posted by greatest.alive

so how is everything working out with your springs now??

Thanks for asking. Since my first post, two changes.
1) the front has now dropped another 3/8th inch for a total front drop just shy of 1.5 inches (normal). The rear has remained generally unchanged for a total of 2 3/8. However, the reverse rake is gone, she is almost perfectly equal to front and back. I like it. I now believe Eibach when they say my stang was in the upper limits of height from factory (2009 vert they think). So, although a radical 2.5 inch drop for the pro-kit, they settled in to a desired height.
2) my attitude has changed. I am more OK with the less than ideal ride and the hitting bottom (hoping someday when I do get new dampers I get a measurably better ride). Interestingly, and thanks to some of you on AFM, I found that going too slow over bumps makes the bounce-down greater, due to the progressive springs. That is, as times, I now go over bumps slowly but without riding the break, the spring seems to tighten up when the tire hits the bump and the "bounce-down" is not as severe and I do not hit bottom on the speed bump. I have noticed that I only hit now on bumps and dips I do not know or mis-judge (or forget to pay attention to...my own driveway insists I remember!

Originally Posted by billthecougnut

So I was thinkin about it, and wondering how a new set of springs would make your differential lower, and the answer I came up with is is THEY CAN'T. The distance beteen the bottom of your tires and the bottom of the diff hasn't changed since the springs have been put on, so I wonder if your pinion angle has changed enough to make the pinion stick down lower than it did in the past, and that is what is hitting. That is the only geometry that would change with the springs. There is a way to re-adjust that, but I am not a suspension guy and I don't know wich part adjusts that. Maybe the rear controll arms? I am pretty sure its not the panhard bar, but those bars that come forward from both sides of the axle and connect to the body. an adjustable set of those and you might be golden.

You make good points. Since I have had no rear-end alignment issues I am sticking with my solid panhard. Since the car is even, I am hoping the pinion angle is good too (have no tool to measure it so waiting to get it on a rack with such a level). Worse case, an adjustable UCA.

Something I have noticed: I do believe suspension issues are more impacted by verts than we sometimes give it credit for. Vert suspension looks different. Not until I recently looked under a new GT (to see how its front sway bar was connected) did I noticed this (my last two Mustangs were verts). There seems to be a lot more bracing on the chassis. My vert has a sort of A-frame up front (not sure what it is called but clearly is a major piece of hardware) and the rear has extra "braces" as well. Maybe (now I am really guessing), these added pieces hit first and, as well, create different dynamics when it comes to suspension.