OK, that makes sense then. Not sure what happened to the PM, wasn't ignoring you.
The key to making power with any engine is the cylinder head, regardless of displacement.
We did 3 months of port shape development and sacrificed a few heads before we settled on our current design. We now CNC machine the ports, the intake manifold, and the combustion chamber. This provides extremely good consistency and speeds up the process. All 5 valves are replaced with oversize stainless valves, the guides are replaced with high perf guides (all 5, not just the center intake), and the seats are reshaped with a Newen seat cutting machine. The Newen is able to cut any shape or angle that you want. It is a $100,000 dollar machine and even Ferrari uses them to do their F1 heads. Just the valve seat shape alone picked up 10 cfm of port airflow versus a typical "performance valve job". We finish it off with new springs and titanium retainers along with some different valve stem seals. Our finished head is flowing over 300cfm on the intake port.
The cylinder head is an exchange program. You send in your stocker (or the whole engine), and you get a race prepped head back.
The CNC finished head retails for $1289. This is not the cheapest head work out there, but I believe it is the best.
PM me for Rhinotalk pricing and details about the rest of the engine.