GM Repair Problems? Ask GM Repair Expert Now.
The spark plug gap should be .045. .060 is too wide and may cause misfire issues. If you have not done so, I would suggest that you replace the distributor cap and rotor, as these can cause issues as well.
MAP sensor is not likely to cause a problem like what you are experiencing. If the MAP sensor were far enough out of spec to cause driveability problems, you would have a lean or rich condition.
Is check engine light coming on?
Do you have access to a scan tool that shows live engine data?
That would be best. Even if no codes are setting and no check engine light is on, the live scan tool data can show the various sensor readings, that way you could read a live misfire, or see if the engine is too rich or too lean on one of the banks, or see if the computer is pulling back timing due to a faulty knock sensor reading, etc.
You are very welcome.