93 econoline 351v8 deadscylinder

Hello
I just put used heads on a used 351 motor.The #4 cylinder seems to be dead. When i pull the plug wire off and on there does not seem to be a difference at all. The first thing I did was check for spark and it turned out to be fine right down to the plug. Next i checked for injecter pulse and it was there. I also ohmed it out and it was pretty close to the others. The last thing I did was a pressure text and that also turned out good at 150ish.Although I did not test #4 cyl while the other plugs were out.
Also I the exaust fuems seem to be a little stronger than the average.
If any one can help that would be great.
Thanks

When you say the #4 cylinder is dead, does it mean it has 0 PSI?
Check each spark plug for any defect.
How's the engine running at IDLE rough?

I agree with Slade901, but in addition I think that you should check the compression in ALL the cylinders. If the compression is acceptable, and you have spark to all cylinders but still have a strong smell of unburnt gas which indicates that you're getting fuel, I wonder if you may have a couple of spark plug wires crossed?

Are the wires run correctly? There are TWO firing for orders for the SBF, which one are you using? The correct one for that engine is on the intake (cast into).