I recently got a 1986 Trans Am with a 700R4. I found that it's not original to the vehicle, as the trans has a hookup for a speedo cable, but the car is wired for a sensor, and the cluster has no cable. It's all electronic. I need the easiest way to convert the trans.

http://tpiparts.net/inc/sdetail/7586

Ok.....what module is this? and will that sensor function to drive the electronic speedo without the cable?

I didnt think that electric speedometers showed up in the f-body until 88. The vehicle speed sensor sends a signal to the vss buffer and from the buffer to the i/p , cruise, ecm.

Ok. But, will that sensor work without a cable? If hook it up to the trans, and I have no speedo cable, and the sensor feeds the buffer, and from buffer to IPC, the speedo should work, correct?

you stated on post #1 your transmission has the provision for a speedometer cable. The retrofit vss will attach to the transmission bullet.You can buy a 7/8-18 cap nut too plug the end of the vss.

Ok. One other thing. Your schematic shows a 4000pulse/mile output to the cluster and a 2000 pulse/mile output to the ECM. Since the VSS you showed me is a 2000 pulse sensor, and I'm assuming the module in the drawing is the speed sensor buffer, does the buffer convert the 2000 to a 4000 signal for the cluster?

you got it, you might also want to figure out what rear end ratio you have and tire size. If the drive and driven gears in the transmission are incorrect your speedometer will be off. You can correct with the proper drive or driven speedometer gears but these are getting harder to find for the 700r4 if that is what you are using. Another choice to correct the speedometer is dakota digital sgi-5 .