I am helping a buddy set his timing on his '99 Chevy Truck. Yes sorry not Chevelle related but I would like to help him set and confirm his timing. He says he has replaced the wires, cap, coil and plugs and the motor starts easily sometimes and other times it turns over a bit before it starts. In addition, he mentioned it runs smoothly when warm and terrible when it is cold (currently winter time in Alaska). The motor is a stock 350 with the HEI and vacuum advance. I have a timing light and have a question about how to set his ignition timing for his application. I am a novice when it comes to setting timing and looking for some input. I would assume I would disconnect the vacuum advance line and plug it and connect the timing light to the propoer spark plug wire and start the engine to identify the timing at the balancer. Could somone provide me with a brief step by step procedure for verifying and setting his ignition timing? Any help would be greatly appreciated! Thanks in advance!

How do you end up with vacuum advance on a '99?

There are so many vacuum lines under the hood (haven't had my head under the hood yet) I assumed it would have vacuum advance. I guess I am mistaken. Any input would be appreciated.

Nope. Don't touch the distributor. According to the GM service manual, there are a few things that need to be checked before adjusting anything. Most of them take a Tech II scan tool to display the information from the PCM.
Most of the info points to the fuel system. The fuel pump and regulator to be specific. Need to verify the output of the fuel pump. These Vortecs take a high pressure to run correctly.
Might be worth an hours diagnostic time at a dealer to point you in the right direction.
Need to specifically check-
1. Fuel pump pressure and verify the pressure is holding with the pump off. (leaky check valve in the pump, or pump getting weak)
2. Check and compare the temperatures the coolant sensor and Incoming air temp sensor are showing (at cold start)
3. Throttle Position sensor.
Be careful, if I remember right, these distributors are noted for having a piece that wears out and it is easier to replace the whole distributor than to repair it, but some models take a scan tool to put it in right and make it work.

Be careful, if I remember right, these distributors are noted for having a piece that wears out and it is easier to replace the whole distributor than to repair it, but some models take a scan tool to put it in right and make it work.

Sounds kinda like the problem I was having on my '97. I highly recommend you pull the distributor and check the gear as these have a tendency to wear and cause that kind of grief. Easy to fix though, just put a new gear on.

Thanks guys for the responses and the information. Swapping out the distributor gear and/or the distributor entirely is easier for me than setting the timing :)

I will have him take it to a shop to run the codes to see if there are any major errors and proceed from there. Thanks again for the input!