How do you set the timing on a 350 chevy engine in a 1995 G20 van?

If the distributor hasn't been taken out, the timing can be set manually but you have to disconnect the distributor wire behind the glove box inside the cab. Tan wire with white tracer it is taped up to the a multi wire harness but is the only one with a single plug. Disconect the plug and use your timing light on the timing mark to set timing per specs. Rotate the distributor as needed to advance or retartd as required for the correct setting. tighten the dizzy clamp and plug the tan wire back together. The computer will now be fooled asd to what the base timing is and advance from there.
Contrary to popular belief, 96' and up do not have this wire. Timing has to be done with a programmable scanner.
Dan
Hope this helps.

Ignition timing, valve timing?

I’m reading that timing connector that needs to be disconnected on a 1995 G20 5.7L is located on the back of the distributer?? Can anyone confirm or correct that.

I though it was a wire with a grey connector near the fire wall .. but that wire has a tan/Blk on one side of the connector and a green on the other...

My mechanic neighbor had pointed that out as being the timing disconnect but after doing the timing it cuts out when you give it gas and it’s not right.

It was running much better before and the gun showed it was about 12-15 degrees advanced ... (with the computer still in charge, if I unplugged some unrelated connector as I now suspect)

Anyways failed smog in CA blew a little high on HC and the rest was fine.

Also, runs super cool, think the thermostat may be stuck open. Mechanic says that can cause it to run rich and not burn all of the fuel ... hence higher HCs scores

The following link showes he wire and how to locate it and set timing
1995 GMC Sierra V8 5 7 Distributor Timing