Tom - thanks, you confirmed what I suspected about the ring gap - it's just about the ring and combustion temps, not the piston material.
Yup - the US treated me fine, I enjoyed myself immensely, even though I sadly associate with Gasholes.
That was my second 'Fling, pretty sure it won't be my last.
One day I might even get my own car over. In the meantime I continue to apologise for all the Ch**y engines my countrymen fit into their Cobras.