If you are making 500HP+ you will no doubt notice a traction issue in mustangs. If they aren’t spinning they are hopping like a banshee.  I have wasted money on different suspension parts and even gimmicks like the kenny brown brace (designed to reduce wheel hop) with little results. One set of Nitto 555Rs and problem solved. If you have never driven with an oversized sticky nitto on regular roads you will be stunned at how much grip they have.  Where once you were spinning you are now stuck like glue and propelled forward with blurry vision.  Simply fantastic, I have had a set of these on both the Cobra and the GT500, go 305 or wider!