I am getting ready to swap a 2rz into my 85 pickup. I have read all the assorted posts and have one question remaining before I dive in. The ECU requires a signal from the electronic speed sensor but I would like to keep my mechanical speedometer. I found some sensors that do both but they are proud of them. Reading one of the tuner web sites I found that the speedometer puts a signal out that might work, I don't remember which pin off the top of my head. They are using this signal to fool the ECU for RPM purposes. Would this signal work for the speed sensor signal for the ECU or am I better off getting a mechanical/electronic speed sensor. Could someone point me in the most affordable direction for one of those if that is what I need?