Cool, thanks for the info, it really has helped me out alot. Im thinking of getting the exhaust done first, as I want the "Mustang Rumble"
. I already have done the K&N filter thing. Ill then do the underdrive pulleys and then the 4.10's.
With the 4.10's, I have heard that you can never adjust your speedometer to be acurate again, even with the correct gear in your transmission. Is this true? I appologize for asking so many questions, I just want to do a lot of research before I make any purchases. Thanks everyone!