Cylinder 3 is misfiring and I'm starting to run out of theories

[modelageek]

There's a pretty good machine shop close to me I'm hoping their salvageable. What did they run you?

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I paid $280 for 2 heads in April 2014. Dover Cylinder heads College park GA. Total for everything, bolts, gaskets, plugs & wires, oil & filter, t-stat, coolant etc was $500.

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[fyyffky]

So what happens with valve recession anyhow? Does the valve hold open the amount that it is recessed when it's assembled with the rockers and pushrods in place?

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[Cemeteryxgates]

So what happens with valve recession anyhow? Does the valve hold open the amount that it is recessed when it's assembled with the rockers and pushrods in place?

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The seat can beat into the head or become dislodged and hold the valve open any cylinder pressures below 65 constitutes a valve train issue

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[modelageek]

If you do pull the heads check your timing chain cover gasket for leaks, its a common fail. You want to replace the gasket at the same time if needed.

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[fyyffky]

So I was cheap and replaced the head on 1,2 and 3. 4,5 and 6 have 85, 100 and 125. Idle is much better but is rough when you accelerate until about 1700. Does just the same in neutral. I've checked everything and put anti fowlers on the rear o2. Anything to look at other than the 456 head? It's not real rough but it's noticable.

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