I know that on our 94+ LT1's we use an electronic Speedo's. Are 93's the same or do they use mechanical speedos. Also do 94+ T56's have mechanical speedo on them (looking to swap into the stang)

 

93's are mechanical. Hence, the inability to make speedo corrections via tuning.

 

but you can run a 93 t56 in a 94-97 car with no problems. So do the 94-97 also provide the provision for a mechanical gear?

 

Call D&D, they have recently designed a mechanical speedo system for the T56 for retro cars. There is a reluctor ring on the output shaft of the T56 which a sensor reads and the PCM translates the information from pulses per driveshaft revolution to MPH