Are upper and lower control arms worth it?
 

I have a 2000 mustang gt that i am setting up for drag. I was wondering if a set up upper and lower control arms are worth buying and what all do you gain from them. I am upgrading the axles and differential and was wanting to do the arms at the same time. How do they help drag racing.

Depends on the arms you get. For the most part, they help by eliminating deflection caused by the c-channel construction and rubber bushings. This lack of deflection reduces the amount of wheel hop that occurs and let's you put more throttle into your launch. If you get traction arms for the lowers, they do this, plus relocate the instant center to help the chassis lift and thereby further increasing your traction at launch. Adjustable arms let you play with the pinion angle to reduce powertrain loss or those with spring perch adjustments, play with wheel loading. However, arms are not created equal. The best ones have a spherical bearing at one end (like Currie, Global West, and Maximum Motorsports) or at both ends (racing parts). Unfortunately, I'm only aware of Lakewood that makes traction bars, which uses poly bushings on both ends. For lowers, this is acceptable but for uppers, make sure at least one end has spherical bushings.