lowering the uca 1" will not bind the factory ball joint and no wedge kit is needed. 1" isnt enough for best suspension performance BUT its all you can go with stock parts and that why Arning only did 1". 1.375" is ideal BUT that requires either a negative wedge kit or modified factory uca's that www.meacomotorsport.com
does. i know this post is old but it was resurected and i thought i would add some info.
Absolutely correct. The Shelby 1" UCA lowering is a compromise because of the ball joint.
The ideal is to have the center lines of the lower control arm as horizontal as possible. This makes the oil pan very close to the ground. Too close for stock springs.
Mine are lowered 1.5" but you need to use ball joint shims with that. You are also going to need to do something with bumpsteer. It will be brutal if you don't.
Every car reacts a little differently but the roads are so bad here, when you hit a buckled road joint or the equivalent, it felt like the car was going to do a sudden 90 degree turn.
I'm using the 680# springs from the Boss 302 Chassis modification booklet recommendation and I'd recommend them over the stock springs. They are very comfortable and you eliminate the probability that you will bottom out on your oil pan at speed with the stock springs which is something to consider.
Before you even go and say I'm not going to track this car, let me define my term "at speed" as anything over about 50mph. Are you going to go faster then that or just back this thing onto and off the trailer? If so, you need the better springs.
Most of this I needed to learn the hard way since there was no one around who knew anything about these modifications on a Mustang when I did them.
Admittedly I can be very stubborn too and learned much through tough love. It may be tied to the type of person who is attracted to Shelbys? It seems to be very common around them?
Granted it is difficult to know who and when to listen to so I suppose you are going to have to learn by your own mistakes.
For you to get the correct results from this modification, you can not pick and choose what parts you want to use. You will find that there were additional parts that you NEEDED to do also. It tends to be all or nothing, and the stock springs are not the way to go with this.
You definitely can and probably should play with various alignments to get the car where you wanted but much of this stuff has already been discovered and you can save yourself a lot of trial and error.