Cylinder six misfire

Problem started with a P0300 random misfire, I have never had a check engine light before in this vehicle. I replaced the fuel filter, cap and rotor, plugs and wires and ignition coil with no change. Finally found out I was losing fuel pressure as soon as the fuel pump kicked off. I isolated it to the fuel pump and after replacing the entire pump and sending unit assembly the fuel pressure holds for hours and the P0300 code went away, but now I have a P0306. I have tried swapping plugs with another cylinder and then wires with no change in the P0306 code.

I did not pull all of the plugs for a compression check but I did pull 4, 6 and 8 to give me an idea. 4 reads 160psi, 6 and 8 are both at 150psi, so I do not believe it is a compression problem. I bought a cheap inline spark tester and it seems on cylinder six at higher RPM's the light skips a spark every few seconds. I moved the tester to cylinder four to make sure it was not the tester, and it had a nice continuous spark pattern. This leads me to believe it is a spark issue. After this, I tried replacing the cap again to make sure I did not get a bad cap. I am at a loss on what the problem could be at this point. I have heard about spider injector problems with this model pickup, but with the intermittent spark, I am leaning towards it being a spark issue and not fuel. I do not know of a simple test to see if I am getting fuel to that cylinder. It seems to idle fine and I mainly notice the misfire when taking off from a stop and right before the transmission shifts, around 2,000 RPM's.

List of replacement parts:
Duralast fuel filter.
Delphi fuel pump and sender.
ACDelco cap, rotor and plugs.
Summit racing plug wires.
Accel coil.

Any ideas would be appreciated. Thanks