Building a high performance slant engine

You're welcome. I'm going to correct myself and say that the combustion chamber volume should be included in figuring the BDC volume as well as the TDC volume of the cylinder. Also, don't forget to add in the volume of the compressed head gasket material. It won't be much difference, but it will yield a more inclusive result. You are right.

If a smaller combustion chamber volume cylinder head is utilized (not happening on a /6), the compression ratio increases. Although there isn't much to choose from in the way of /6 heads, combustion chamber volume (in the greatest sense) is reduced by milling the deck of the block and planing the cylinder head.

There are some /6 racers on FABO and SlantSixDan occasionally puts in an appearance. They all know a lot more than I do about /6 builds.