Hello folks, this is my first post here, so here goes. I have a 85 Z-28 that i bought without motor or trans. I transplanted a 88 tbi motor from chevy truck with th700r4. Originally the car was a v-8 carbed 5 speed. It has a gear driven speedo cable and the new motor has electrical. I have read that this car has a vss box on or near the speedometer. I know i can change the vss from electric to cable with the replacement on the trans so i can have a speedometer. So my question is can i use the output from the speedometer vss for the input to the ecm so i can use the cable to operate the speedometer? I have the 1227747 ECM and i believe it requires 2000 pulse to work correctly. Or will I have to install a signal generator between the cable output on the trans and the speedometer cable?

 

https://www.tpiparts.net/inc/sdetail/7586

 

Yes, that works. The optical VSS on the speedometer will provide the proper 2K PPM for the '7747 ECM.

It sounds like you understand the required mechanical changes to the transmission. IIRC, will need a tailhousing that has the torque arm mount. Along with the drive and driven gears and cable mounting insert to go with it.

RBob.