[Formulajones]

First I've heard of shielding the blue tach wire. Interesting.

I didn't bother with any shielding on either install I did here 3 years ago.

In fact on both installs I'm using a tach signal to run 3 different things on both cars, coming off the MSD box. The Sniper, the factory tach in the car, and the controller for the 4L80E trans that is in both cars. A lot of tach signals

No issues to date, but I also did similar to what JLMounce suggested. All the wires basically come out of the back of the Sniper toward the firewall. I have the main power stuff going off to one side of the distributor and to the firewall heading to the passenger front side of the car where the battery is, and the other stuff like 02 sensor and fuel pump etc... running around the other side of the distributor and down the driver side of the car towards the back. So once they leave the Sniper they really never see each other again. I hid as much of it in the factory wire looms that I could, the rest of it is behind the fender or down in the frame rail where it can't be seen.

Shucks even the TPS wires are hidden along with the Alternator wiring because it was convenient, the alternator harness already runs along the top of the valve cover so it was natural for the TPS wires (2 TPS harnesses on both cars) to drop right into the existing harness and disappear.

No issues with that either, and I'm running old style alternators on both cars with external voltage regulators.