...One thing you can never be assured of when buying a head like this is the initial machining of the head. All manufacturers are guilty of it, the concentricy of the seat to the port, I've seen seats as far as 3mm off center, which really affects the port flow. Best heads are hand picked for this before any mods are performed.
If you are referring to the port area around the valve seats, my engnbldr RV, os valves, etc head was very badly machined and the valve seats were not concentric. None of the exhaust valve were closing. The valve springs were crooked and not sitting square on the table. The valve seats were so bad that John said the machine work to fix it and install new seats would be WAY more than buying a new bare head and him putting in the valves. He could not confirm who manufactured my head.
There are a number of advertised sources for 22 heads, knowing what I know now, I would only buy from 22RE Performance, LCE, or my local head shop.