I suggest you do springs and dampers when you swap them out. Springs only makes the ride almost unbearable in some situations and the installation cost is the same for installing springs only and springs + damper. I also suggest getting a set of stock GT wheels with performance tires as well. Stay squared set up when it comes to tires. Lower control arms plus lower control arm relocation brackets will help rear grip in autox/track applications. Upper control arms are useless for your application. Swap bars are nice but 80-90% of the body roll will disappear with upgraded springs and dampers. I doubt you will scrape with LT headers since they aren't that low to the ground even when dropped. I would recommend some springs that give you a mild to moderate drop so your dampers have optimum travel for better handling. If you can, have around -2 degree of camber.
Also I agree with the comment that subframe connecters are USELESS. They're for the older mustangs with chassis that are not as rigid as the S197 chassis.
Car: 2011 Black Mustang v6, 6-Speed Auto, Premium Package
MODS: KW Variant 3 Coilovers w/ Maximum Motorsport CC Plates | J&M Adj. Panhard Rod | AEM Intake | Bama 91R | Borla S-Type Axle-Back | Boss Front Conversion w/ Saleen Grille + Foglight w/ Auto Headlight | Boss Rear Diffuser | Forgestar F14 18x10 +42 w/ Nitto NT05 275/35-18 (all around)| BMR LCA | SVT GT500 BBK|
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