2007 4.3 GL-G ignition timing

[Dave-R]

I am getting a lot of different information on setting the initial timing on this engine. I have the shunt, and a timing light, and have followed the procedure outlined in the Volvo information concerning the Delco EST distributors. My timing light does not have the advance feature that new ones do. Do I time it with the shunt on to 1 deg BTDC or to 8 deg BTDC? That is the question I have. I have followed the the initial timing procedure, and do see a change when connecting the shunt to the + battery. I was thinking all chevy short blocks were set to 8-10 deg. BTDC. Please clarify for me. I did set it to 8 deg. BTDC and it runs rough at idle and low speeds. Thanks Dave-R.