IMO the non WC, T5s aren't that swift. Here's an article that might help you out. They aren't that difficult to rebuild but IMO you should hunt for at least a WC T5.
If it says WC T5 , it probably won't work on your car.
Ford began using the Borg-Warner designed T5 in small passenger cars in the early 80's. However these early non-World class (NWC) models weren't suited to handle the power of modified V8 engines, and it wasn't until the availability of the World-Class (WC) T5 gearboxes designed for the new fuel injected 5.0L Mustangs that the popularity of the transmission took off. Compared to NWC T5's the WC's benefit from needle bearings under the gears and tapered roller countershaft bearings for reduced friction. This change also allows the later to run considerable less viscous ATF fluid rather than heavy gear oil. The blocking rings are upgraded from brass to fiber lined steel for smoother gear synchronization. The early WC T5 versions were rated to handle 265 lb-ft of torque, while subsequent changes to gear material and size in 1990 bumped the torque rating to 300 lb-ft. The 1993 Cobra T5 was rated to handle 310 lb-ft, while Ford Racing's aftermarket "T5-Z" could handle 335 lb-ft as a result of a smaller first gear (2.95:1 compared to 3.35:1) and stronger steel.
T5 Transmission Rebuild - G-Force T5 - Modern Driveline - FordMuscle