What wire do you disconnect to set timing on a 350 in 94 Chevy pickup?

On a 1994 Chevy 350 pickup, you don't disconnect a wire to set the timing in the traditional sense. That's because it has an electronically controlled ignition system managed by the PCM (Powertrain Control Module). There's no distributor with a mechanical advance to adjust.

Attempting to adjust the timing by disconnecting wires would likely damage the system or lead to incorrect timing. Instead, you would need a scan tool capable of communicating with the PCM to access and adjust the timing parameters. This is best done by a qualified mechanic or using a professional-grade scan tool.