The SHELBY DROP!
The famous Shelby drop. What is it? Well if you are a classic mustang fan you have heard of Carrol Shelby and you probably know that he raced mustangs. One thing that he did to improve the way these car handled was to drop the Upper Control Arms (UCAs) 1" down and 1/8" over-towards the rear for '65/'66 cars and 1" down on the '67/'70 cars.
By simply drilling two new 1/2" holes (17/32 to be 100% accurate) you can make a huge improvement in the way your car handles. This free mod only comes with one catch. You will want to have a 'performance alignment' done as some folks call it. I have not done my alignment yet but I do plan on doing it myself. These are the specs:
1. +2.0 to +3.5 degrees caster.
2. -.5 to 0 degrees camber.
3. 1/16" to 1/8” toe in.
OpenTracker provides the template here if you want it: www.opentrackerracingproducts.com/photos/template.jpg
Now some folks will drop the arm more than the 1" but these are the folks that do the track racing so there is added improvements there. Do you own research on this. On my Favs page there are some urls to forums where you can find lots more information on the UCA/Shelby drop. It is well worth the time, effort, and the low cost of an alignment.
Pictures below are of my new Shelby Drop holes for my UCAs.