Starting in 1983, Ford introduced the Mustang platform to the latest and greatest upgrade over the factory 4 speed manual transmission to the T5 platform. These were classified as the ‘Non-World-Class” T5 5 speed. This application was rated as 265 lb/ft torque rating and was a well-deserved upgrade over previous years. The 83-84 years offered the following internal gear set options- 1st- 2.95, 2nd-1.94, 3rd-1.34, 4th 1.00, and 5th-.72.
1985 then introduced the newer World-Class T5. This transmission still had the same overall power rating of 265 lb/ft but upgraded internal gearing made this a better application for the upcoming changes over to electronic fuel injection. The 85-89 internal gear set options are as followed- 1st- 3.35, 2nd-1.93, 3rd-1.29, 4th 1.00, and 5th-.68.
Next, from 90-93 the World-Class T5 got a few internal upgrades. The power rating on these models jumped up to 300 lb/ft and also upgraded bearing races and synchro’s. Other changes also included an upgraded shifter, and speedo drive gear options for easier gear correction fixes. 90-93 internal gear set options were- 1st- 3.35, 2nd-1.99, 3rd-1.33, 4th 1.00, and 5th-.68. This 3.35 first gear was a HUGE improvement over previous models.
In 93, Ford also had one other variation of the T5 that was limited to the SVT Cobra Mustang. This “Cobra Spec” option was the first of its kind to have the tapered input shaft bearing and improved front bearing retainer. They also included a new reverse gear braking system and synchro whereas previous models lacked these functions. Torque rating was bumped up to 310 lb/ft and internal gearing remained the same.