the head bolts showed are  nothing like the originator replacement grad8 cap screws. the bolt showed incorporates a flat washer and bolt 1 part
why not machine a small a mount just below theboltwherthehead of bolt touches the head casting

Thanks, Ted. 

Yes.

Lorena, Texas (South of Waco)

Thank You for sharing that info Ted ...

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Ted, does the same +/- 0.001 also apply to ECZ-G heads? 

The ECL-A heads require a 0.0063” cut for each combustion chamber reduction of 1cc.  If the heads get progressively larger (or smaller depending upon your perspective) from one end to the other, then that 0.0063” number can be used to mill the heads accordingly to equalize the combustion chamber volumes.


The intake bosses have no measurement value related to the thickness of the Y cylinder head.  As a general rule, the four bosses on the exhaust side of the head for head thickness/milling purposes are all the same size but it’s the two center ones that are the ones specified by Ford when checking the heads.  When milling the heads, it’s not unusual for the end exhaust side bosses to differ from the two center ones depending upon the warpage of the heads.

As Jeff brings up, it is possible to mill the heads a different amount end to end by design to equalize the combustion chambers.  I get away with as much as 0.020” difference from end to end and not have any issues with the intake manifold sealing as it should.

The actual Ford spec for the thickness of the two inner bosses under the exhaust ports for the Ford Y is 1.000 ±0.001”.  There are some exceptions to that and TSB #973 lists one of those exceptions.  Here’s TSB 973 but it’s in a bound book and does not copy well at the binding.
  

Lorena, Texas (South of Waco)

Good question. The experts (Mummert & Eaton) told me to measure the center pads, near the spark-plug holes. If the heads have not been milled, the pads should be 1.010". Compare the heights of the center pads to the heights of the end pads, in case the heads were milled more on one side/end. As Ted said, measuring the combustion chamber volumes also helps. 

Although Ted did say that it's possible for one side (front-to-back) of a head can be milled more than the other, I've not been told (or read) anything about measuring the pads on the intake side. Maybe misalignment of the intake manifold confirms the same thing. 

While I have all the expert FYB people gathered, there is one more thing I would like to ask concerning the FYB CYL HEAD -

The pads @ the bottom of the head, they are used to determine deck thickness before and after machining, correct?

On the EXH SIDE there are four pads. Are all four used to determine squareness?



There are also two pads (?) on the INT SIDE (@ bottom runners). Are these used also?



Again, THANX! for the info ...

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HE POSTED -

The numbers I see are ECL6090 with an "A" over top of the 0 . Other number 4BA.

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10-4.

Let me see if I can get it. It belongs to a poster over@ FORDBARN.

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