Here's why these Upper Control Arm kits are better than leaving the stock suspension geometry alone:

Question: Was the Mustang designed for drag racing from Ford?
Answer: No. The Mustang suspension was designed for driving around town in comfort and a little bit of handling. Ford had no intentions of designing the suspension for maximum straightline performance which is what you want from your Drag Car.

Ever look at a true 4-link cars suspension? When you look at a tube chassis car equipped with a 4-link you will notice that the lower control arm is horizontal with the ground while the upper control arm is angled down. These angles are critical for locating the Instant Center for Drag Racing for the best hook and best stability which is why there are so many different holes to choose from. The Instant Center position DOES make a difference.

Stock Mustangs were not made for Drag Racing and have the upper arms horizontal with the ground and the lower arms pointing upward, just the total opposite of what is needed for a Drag Car. If you are serious about Drag Racing then you should be concerned with how your chassis and suspension is set up as a complete system. The Mustang platform is a great starting point but finish what you started when you decided to do some drag racing and get the suspension set up like a drag car should be. Chassis plotting is included with a purchase of any of the Prolaunch #1, #2 or #3 Upper Control Arms kits and this is a first step in getting the suspension set up for a Drag Car.