Guys:
I know I'm very late to this post but here's another idea that might be worth investigating. Just for "grins", you might look at Ryan Falconer's web site, specifically regarding the incredible V12 he produces. Using one of these (cross flow) heads should produce some really good flow numbers.
A couple of interesting points:
1) The cylinder spacing of his V12 is the same as the SBC (at 4.40" if I remember correctly) and I believe that is the same as the 230/292 six so I'm guessing things will generally "align".
2) I'm assuming you would want to use the passenger side head. Like the SBC, the head uses a 5-bolt patern so much of the same block work would be required as building and using a composite head from V8 castings.
3) I'm not sure but the intake/exhaust valve order may be different (front to back) so the cam selection might be a real challenge - probably would be a VERY custom item.
4) It appears to me that the individual port FI for the V12 is a 3-part casting (left intake, right intake, and valley cover?) so I'm guessing that the appropriate side of the intake could be used without requiring a bunch of additional fabrication. The exhaust side would need to be a custom piece and I'm not sure what you'd do about ignition - perhaps a coil-per-cylinder setup?
From reading Leo's book (specifically regarding his experience with composit heads), there is no doubt that there is considerable work involved to both build the head, and then mate it to the inline six block. I have no idea how expensive one of Falconer's V12 heads would be or if he would even part with one. But its an incredible piece and would at least eliminate one major part of the fabrication. Anyway, just something to look at and perhaps think about. If I could lay my hands on one of Mike Kirbey's heads, that would probably be the best bet ...
