88 GMC 383 Stroker

OK, I have a 700r trans in my truck and on the tailshaft it has a electric plug in with a purple wire and a yellow wire coming out. Is this the VSS wiring or is it the electric speedometer wiring or is it both? Can I disconnect this and put on a new tailshaft with a mechanical speedo or would this be bad? I'm lost on this one.

Dock Rocker

If it is a two wire thin flat harness that is the speedo sensor. You cant just swap the tail shaft to go to a mechanical speedo. You will need to remove the tailshaft and remove the metal pickup ring on the output shaft and install the plastic gear for the mechanical pickup. This is not really easy to do on the truck as the ring is pressed on, and you will need to get the plastic ring on the output shaft for the mechanical drive. Then you will need to pull the screw off of the other side of the terminal where you currently plug in the electric pickup. That whole piece will pull out and it needs to be replaced with a mechanical sender. You will then have to run a mechanical line from the trans to the new speedo.

If this dosent make sense PM me

88 GMC 383 Stroker

OK, that sounds like a lot of work and expense. So I can just hook up a electrical speedo to this and it should work fine? Thanks for the help.