Engine Missing after head gaskets

Here I am, hoping someone can help me out. I've just spent hours of effort, toil and sweat replacing the head gaskets in my 1995 5.7L TBI Suburban. After completing the job I am having a problem. The 2nd and 3rd cylinders on the passenger side (firing order of #4 and #6) are not firing. I have spark all the way to the plug on both cylinders but they are not firing. I have also checked the TBI and it's pumping plenty of fuel. The only clue to what might be happening is this: While cleaning the intake manifold, I noticed one of the passages (can't remember where it was located) was clogged with what I thought was oil or carbon. I used a screwdriver and broke through the stuff and cleaned out the passage. Upon examination, the "stuff" looked more like an epoxy plug. I went ahead and left the passage clean and replaced the manifold. This engine does have the back coolent passages blocked by the gasket, but the passage I unblocked was not a coolant passage.
What could be happening? I am at a loss and don't really want to remove the intake manifold unless necessary!!!

Here I am, hoping someone can help me out. I've just spent hours of effort, toil and sweat replacing the head gaskets in my 1995 5.7L TBI Suburban. After completing the job I am having a problem. The 2nd and 3rd cylinders on the passenger side (firing order of #4 and #6) are not firing. I have spark all the way to the plug on both cylinders but they are not firing. I have also checked the TBI and it's pumping plenty of fuel. The only clue to what might be happening is this: While cleaning the intake manifold, I noticed one of the passages (can't remember where it was located) was clogged with what I thought was oil or carbon. I used a screwdriver and broke through the stuff and cleaned out the passage. Upon examination, the "stuff" looked more like an epoxy plug. I went ahead and left the passage clean and replaced the manifold. This engine does have the back coolent passages blocked by the gasket, but the passage I unblocked was not a coolant passage.
What could be happening? I am at a loss and don't really want to remove the intake manifold unless necessary!!!

What you unclogged was the EGR passage..no problems there.
I would look towards the possibility that you may have tightend the rockers a little too tight.
Also check to see that the firing order is correct 18436572

Thanks for the advice. Which rockers would they be? The exhaust or intake?

I would check both..it doesn't take but a 1/4 turn too tight to cause a skip.

I cannot thank you enough for your advice. I am going to work on it today and see if that takes care of the problem.

Thanks so very much

joe

Thanks so very much GMMerlin. I readjusted the valves yesterday and the old suburban has not ran that good since new. I would have never guessed that the valves being slightly tight would have been the issue. Once again, thank you, thank you, thank you.

joe