This is on my brother's 98 Carmaro by the way. Before the plugs/wires were changed the car had a bad low speed misfire that caused noticeable driveability issues. After the plugs/wires that problem is completely gone, but at 3K rpm's there is a misfire and the tach starts bouncing around a little bit and the car stutters. All the boots are snapped on to the plugs and coils tightly, what else could be causing this?

 

I replaced the ignition coil for cyliner 5 and that fixed the problem. Thanks guys.