Shaz,

Yeah, I get it. As you know, I'm also a full-size pilot, so I understand about thinner air at altitude. Thing is, not all of the people saying a P-80 is marginal are flying at altitude (or clarified that their assessment of that engine's suitability was specific to George's altitude). Go look at the comments (and where their authors are from) and you'll see how the altitude component didn't seem like the main thrust of the question. If they did, then I withdraw my comments!