how do you retrofit a 1990 1/2 ton silverado speedometer to work, that has a 700 r4 trans ( gear driven type speedometer) with an attached 1990 speed sensor tail shaft ( is electrical ) ? how much would it cost, and where is the cheapest place to get it, thanks, ron. --------mustcam@atsbcglobal.net

 

Huh?..both are from a 90?

 

Dude I think your question needs to be more specific? Retrofit it to do what? The gear driven cable go's directly to the speedometer and the one on the tail shaft will go to the pcm. That being said what are you trying to get at? This should be where GM placed the vehicle speed sensor for that year I think, if I remember right.