The Irs From A Tbird Is Going To Be Too Wide To Even Think About Putting It In A Mustang Without Serious Modification. Muscle Mustang & Fast Fords Had Several Writeups On Irs In A Fox And Sn95 In The Last Year Or So. Itwill Work In A Sn95: Try The New "edge" Cobras- 99-04 Cobras All Had Irs In The Rear. Good Luck.