How did I miss this so long??? Yes, the 03 Cobra IRS is the best of the crop of the 99 up cobras which all have IRS or I should say 03-04, I would think they are the same, they have extra bracing, developed in the Cobra Rs., and 31 spline drive axles, but yes, the Cobra is more designed for road racing, road handling, not for drag racing, a lot of guys buy them for the power then want to drag race, when they have problems or envision problems with the IRS failing on the strip they want to switch to straight axle, I was more than happy to relieve one of this excellent handling and riding rear end since as Danger Dude said, I am into handling, not drag racing, I like to watch drag racing, but my mods cost me too much money and effort to tear up on the drag strip.
Rick Kilpatrick, AAS Automotive Systems Tech, Alamance Community College, Class of 99. 06 5 speed manual Mustang with Pony pkg : GT Mac Mufflers, true duals with one custom pipe. 2.5" system. GT bumper cover, all installed March 7&8 2006. AFE Stage 1 CAI, Motoblue Underdrive pulley, GT aluminum shifter knob, honeycomb rear blackout panel,and dash kit installed. Roush hood scoop and side window louvers installed. SS taillight trim has been installed, new alum. GT steering wheel installed.