So my cousin and I swapped his tranny last night since it was going bad. He bought a used one from some guy. We got it in and it works fine, BUT we have no speedometer. His truck is designed with an electronic speed sesnor, where as this trans is a mechanical/cable run speed sensor. Now I know you can not just take the one out and sway the other in. What I was wondering is dose anyone make an add on, that can connect to the tranny's Mechanical speed sensor output, and turn that signal into an electronic output that we can plug the stock speed sesor wire/plug into it? let me know if anyone has heard about anything like this. thanks guys/girls

 

Go to a site called "jagsthatrun".... they have interface solutions for many GM trannies. They make a 40-tooth reluctor gear/sensor that can be mounted on the differential housing.

http://www.jagsthatrun.com/

http://www.jagsthatrun.com/Pages/Par...ctor-Diff.html

There is also some stuff at Dakota Digital for speedo interfaces and conversions:

http://www.dakotadigital.com/

My TH400 has an electronic sensor from a late GM pickup tranny. Might be just a matter of swapping in a later tailshaft housing with the correct reluctor gear and the mount for the VSS sensor.