A picture is worth a 1000 words. For those whom I've confused, or just curious. There were two Cleveland heads cast in Australia.
The heads below are the popular ones, from the Australian 302C. They are what an American would call a 2V head, i.e. small ports and small valves. They are however the only 2V head to have a small "quench" style combustion chamber. But of importance to me, notice the extra width of the flange to the right of the exhaust port. This allows 4V headers to be used with these "2V" sized heads. Headers such as the Euro GTS, Group 3, GT5, and early GT5-S exhaust systems.
This second set of heads pictured below are from the Australian 351C. Like the previous heads they are what an American would call a 2V head, i.e. small ports and small valves. These have 14cc larger "open" style combustion chambers. But, like the 302C heads, they have the same extra width flange to the right of the exhaust port.
These are the heads I'm hoping to find.
