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78 cc on the combustion chambers which I believe means they were only cleaned up not milled. Mopar Muscle article says the 915 heads were 78.5 cc stock. My stock 906s were about 88 cc IIRC.



The mopar muscle article is WRONG , The 915's I have are 81ccand the few sets of never cut 906's I have done or had done have never been less than 90 cc , some as high as 92cc.

Get a pair of dial calipers and measure the thickness of the head bolt boss under the exhaust ports this will give you an idea how much they have been cut, factory heads seems to be 1.000 .



Boss measures 1.000 - 1.003"
When CCing a chamber do you try to keep the fluid level to the head surface or allow it to "baloon" upward?
With the heads perfectly level I filled the chambers so the water did not extend above the head surface - this gave me the 78 measurement. If I allowed it to protrude above the head surface but not break over the edge of the chamber it was closer to 81 CCs.
I would think it needs to stay level with the surface myself but not sure about correct procedure.