Factory heads - How consistent are your CC #s???

Just curious what others have seen for variation in combustion chamber volume measurements when CCing heads???

Just had a set of 906 heads freshened up at the machine shop and my combustion chamber volumes vary between about 82/83 and 86 CCs, IIRC.

Based on everything I hear about the lack of consistency in Mopar factory tolerances, I assume this is pretty normal??? What have you guys found?

Also, any general consensus on how close these numbers should be for a well built street motor?

Thanks

Not the same heads but I recently did some 452's , 1 to 1.5 cc difference , but I did a bunch of machining to the open part of the chamber.

I just did some math and you are looking at .27/.36 difference in compression from the 82/83 to the 86, I used a .030 over 440 for the calculations. In a mild street motor that's probably not that big a deal.

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I just did some math and you are looking at .27/.36 difference in compression from the 82/83 to the 86, I used a .030 over 440 for the calculations. In a mild street motor that's probably not that big a deal.

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That's what I was thinking. Based on the variability of deck heights across a typical non-square Mopar block, I would think this level of variability would be pretty common and not much of an issue, but my new machinist seems to think it will be a problem.

I guess that before I do anything else, I'll have to bust out the buret again and doublecheck my numbers.