The SROD will bolt right in. You can use the SROD bellhousing from the Mustang and use a cable clutch. However, the SROD is a 4-spd overdrive transmission and has some huge holes between gears. I've owned both 82 and 83 GTs. The 82 had the SROD and the 83 had a T5. The SROD couldn't compare gearing wise to the T5. I was always shifting gears around town in the SROD where 3rd gear in the T5 always seemed just right. T5s are easy to come by, I'd go that route first. Most early GT owners replace the SROD with a T5.