On a 1998 4x4 Silverado with a 350 Vortec bored to a 383 stroker how do you get the onboard computer set for the modified engine to turn the service engine soon light off?

Answer 1

You may need to go to a performance shop for a new chip or who knows what. That's the problem with too radical of a modification. Most engine shops will tell you to not go radical on an engine rebuild if it is to be connected back to the same computer and sensors.