Far as i know there are alot of differences in the Camaro/Firebird T-5 compared to the Mustang T-5. one thing is the shifter location is farther foward that a GM version, that mean it it'll be closer to the dash and may hit. Also The were the bellhousing bolts to the tranny that bolt pattern is different than the GM pattern. I'm not sure about this but i believe that the input and output spline counts are different than the GM spline counts. I've never heard that their have been any t-5 that was innerchangeable between Stangs and F-bodies. I know there is a full list of T-5 applications at BritishV8.org
http://www.britishv8.org/Articles/Bo...T5-ID-Tags.htm whether or not that helps you. But i Hope you find one that will work.