be careful dealing with Speed Concepts. i had a horrible experience with them, as did christorres and a few other people i know...no. you need the whole axle too. Heres a kit that has EVERYTHING, plus you get to choose the gears you want in it.
Speed Concepts - M-4006-AXLEKIT - 1999-2004 Mustang GT/Bullitt/Mach1 and all 1999-2004 Cobra 8.8 rear end axle complete kit 31 Spline & gears
heres what you need to do, PM itschristorres08 ask him what it took to break his rear end, pm 97tunedmustang and ask him how his rear end is holding up, pm atlanticblue99 ask him how his rear end worked for him at the track... you will see very fast that the 7.5 is stronger then you thinkI'm afraid though because I'm a kid so if I blow it I won't be able to fix it for a long time