@Xylonmedia There is another header option, but they may have gone up in price since I bought mine in 2020. The Aussie Wildcat Header. Here is one example of them:
Header Link. I bought mine from Ebay from seller APS8748. I had some questions after install and he corresponded with me easily through email. One thing to be aware of with this header though is that in Australia they aren't concerned with a steering box on the left side of the vehicle, so it is really close to the steering gear, which is a manual box on my '78. So close in fact that I had to remove the heat shield. I've been daily driving it like that for 3 years now though, so it seems to be okay. 1 quick smack with a ball peen hammer might solve it, but I haven't done that yet. Other than that, it is a quality piece, I installed it with a normal Fram gasket without any planing etc. and it has never leaked. The flange thickness is already metric and seems to be right out of the box. I painted it with VHT paint, but that flaked right off, I probably didn't do it right, another thing to get around to one of these days. Anyway, just thought I would add my experience to see if it helps anyone. Here's a bad picture of it, complete with flaky paint:
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