Brief comment:
The Sissell is the only thing available TIKO currently.
The chamber design is a well-developed modified closed wedge, with modern plug placement near the exhaust, and what appears to be good reliefs.
However: it's still a reverse-flow (not a fatal flaw, but certainly not an advantage), and has parallel valves.
If I were going to fabricate a hybrid head, my choice would be a multi-angle chamber design such as the Cleveland (only .020" smaller pitch than the 292), and begin with used alcohol sprint parts to get an aluminum casting for $500. It's as close as you can get to a full cross flow (with opposing valves, like a hemi) and still have a compact chamber.
If that's not enough work, get a late Nissan VQ40 V6 motor (.009" larger pitch) and have DOHC and 4 valves, and fabricate a cam drive.
