The dealerships frown on you adding any mods. They can cancel the warranty immediately and legally. Now, because my Mach would not not shift smoothly from 2nd to 3rd with the 3650 Tremec tranny, they allowed me to add a short throw shifter and still keep the warrnaty. But that was all I could do, and their mechanic had to do it. I have been working on cars since I was a young teenager, and will not work on my 03 Mach1. It is a computerized car, and the computer testers for these cars cost literally thousands of dollars. I change my own oil and that is it. But, nobody has touched my 65 but me.