I see what you are thinking but the answer to that one would be no it would not make a difference. The air gap that I specify is not for a tuning reason it is only to ensure that a sufficient amount of air can flow into the engine (when the throttle is closed) so that you CAN tune your engine properly (by adjusting your needles). So the air gap will stay between 0.5 & 0.7mm (on a broken in engine) but because of your altitude (and hence lesser air density which I'm thinking is what you had in mind) you will have to run a leaner needle setting for instance on your LS to get a steady idle than some one would need to at for instance sea level. The same will also apply to your HS needle setting but again your air gap is for all intents and purposes irrelevant to this once set to the number that I specify. Hope this helps explain things a bit!

Regards,

Ron