Advice from the Experts?
I have owned a few nice cars and had modifications done to them over the last 10 years, but my most recent aquisition was earlier this year of a 2008 Shelby GT500. I have to say that I absolutely love it and it is my most favorite vehicle, but I have never seen so many performance shops throughout the country try to sell people stuff (mods) that are not needed at all. One shop will tell you that you need this pulley and that size lower OD balancer, or don't put that one because it'll cause heat soak, and then another shop will tell you the complete opposite. And most of the shops bad mouth the others in the area. It's absolutely ridiculous. Who do you believe? Everyone is trying to sell their goodies, and that's what it comes down to. Whether you need it or not, it's the best thing and it will give you XX amount of more wHP and rwTorque. Be cautious for sure. Find a shop that you believe in and that won't sell you a lot of useless modifications that will only leave you penniless. And also, whatever you do, I would NEVER EVER do an email tune. The car needs to go onto a Dyno so that you can get real time performance adjustments.
Take it from me and some others like me, don't fall into the trap of listening to someone entice you with awesome horsepwoer and torque numbers and only if you spend $2000 or $4000, $10,000. Plan ahead, think of why you want what you want on the car, and the purpose, then budget for the goodies, but buy from a local performance shop where you have some good testimonials from fellow Mustang people.
That's my two cents on this topic.