As far as I know, it was only the 268 (both closed and open port), 66, and 272 that had the highest angle spark plugs - but it may of course have varied before that as well?
Then, I don't really know if the 66 shared the case with the 266 or with the 268 - but suspect the 266...
Something I believe is true (but can't prove) is that both the 266xp and the 66 was made in Slovenia (at the Tomos/Koper factory) after a deal done in 1991 (after the breakup of Yugoslavia), and that the same factory had made the at least the 162SE (of that saw family) before that. Possibly the 61 as well, but I don't know when that started (and am not 100% sure it actually happened).
The same factory made a lot of other Husky models as well, after production in Sweden was discontinued, mostly before the breakup of Yugoslavia, but that's another story....