it is a 7.5 inch differential and you need one from a 94-98 style as the 99-04 are a bit wider by about .75 inches per side. You can also use a GT 8.8 rear end, same fitment just stronger and has positive traction where yours does not
why are you replacing vs rebuilding or what not?
__________________ 2003 Cobra Vert (Redfire) #3938 of 5082 @ 05/27/2003
472rwhp/493rwtq -Modification List - Dyno Sheet 2012 Mustang 3.7L M6 (Kona Blue) 2011 Ford Edge Sport (Red Metallic)