"What Should The Timing be on 1993 GMC Sierra"

1993 GMC Sierra Left Side View

I have an 1993 GMC Sierra that has a Chevy 350 small block on an automatic 2wd transmission. I have the truck running currently as close as I can to 0* (when the ECU is not changing the timing). I am just wondering if there is any other particular timing amount that I should have that would be better since 0* is what is rated from the factory.

Answer: You can try adding a degree or two (yes, you read that right) up to about 4*, however if the engine starts to knock, which you may not hear, the ECM will pull timing back even worse than it was before you increased it, reducing economy and power.
It is best to start VERY small, and see how performance changes. Don’t try to get past 4*, those setups were not real tolerant of timing increases.

Edit: I assume you are talking about the timing when you have the mentioned EST bypass wire disconnected.