HKS Turbo Timer Type-1 Questions?

I just installed a HKS Turbo Timer Type-1 in my car(92’ LS OBD-1),
and I have 1 problem left unsolved.

I’ve did some searching but I cant find what I’m looking for.

Here’s my question? The HKS Turbo Timer Type-1 has a wire for Speed sensor.
I know that our cars have cable speedometers, but There is a signal pulse wire for the speedo, I just dont know which wire it is.
I looked in the ECU pinout diagram, but it doesn’t seem to quite match.
So basically I dont know which wire to pick? I dont wanna put everything back together in my car until I figuire it all out.
Any help is much appreciated…

Here’s what I’ve done so far.

Red wire-White wire (constant power)
Green wire-Black wire/Yellow stripe (IGN 1)
Blue wire-Yellow wire (IGN 2)
Gray wire- to parking brake wire
Brown wire- to Yellow wire on my Mallory HyFire Ignition Box

Does this help? :hmm: 94