A good GM ignition coil makes engine run smooth and no hesitation.
This is what the coil towers should look like.
A common reason for misfires, hesitation, and  stumble is a corroded ignition coil and/or plug wire.
This example is from a 3.1 / 3.4 litre engine.

Burned / corroded coil tower
Burned / corroded plug wire

This can cause misfires under hard acceleration, or  when cruising at a steady speed (45-65 mph) then  accelerating to pass. Also will misfire at idle on wet,  damp mornings. Causes a
code p0300.
Corroded GM engine ignition coil and spark plug wire causes misfire code p0300
P0300 Engine Misfire Common Causes

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