Miss at Idle 2000 5.3

I recently purchsed a 2000 Silverado with the 5.3 that has about 45K. I noticed that while at an idle it has a hesitation. I had it scanned and it showed a slight miss in cylinder #1 but not enough to show a code. My tech swapped the coil packs from #1 and #2 and the miss was still on #1, so I think that will rule out that. We put in a new injector in #1 and still the same problem. I will be taking it into the shop again but any ideas would be great. Thanks for your time.

new plugs

Better wires do not hurt either...