Cylinder has spark but not firing..

RustyRatRod said
Good GAWD. One step at a time. Compression seems fine. Do you have a volt ohm meter? Measure the resistance of the two wires on the skipping cylinders and see how they compare to the rest. They will be different because of the difference in length, but if they are stupid different then you have plug wire issues. Lets rule the simple stuff out first.

Hyper_pak said
I had a 67 440 with the same problem. Turned out to have 1 valve longer that the others. On a compression check all was ok, but when lifters pumped up it would push the valve off the seat and leak off all the compression. Put a straight edge on your valves and see what the installed height is across all the stems.

first off you need to buy a Ohm meter like Rusty said above.You can get a volt/Ohm meter at any parts store for 10 or 15 bucks. now check the Ohm readings........What are they???? I had a bad set of wire that required me to keep changing out due to growing High Resistence. i didn't make me loose a cyl......not at idle but under load it would cause a popping noise. check the wires, replace the bad one and off i when again. After a year of this silly game. I bought a high Q wire set. no more problem.

PLEASE DO WHAT RUSTY AND I HAVE SUGGEST BEFORE YOU GO ON! One step at a time will get you there.

Now it is possible that the valve job was not done properly,(as Hyper pak sugested) causing this problem. it also could be that with the heads being shaved that the push rod is on the raged edge of being to long now and on cyl #1 and 8 they are two long.

The block that i had square decked (cut the deck to be square with the crank) was lowest at #1 and at the rear #8 before it was decked.