infernal, go pick up some O'donnell from MSH. everything ran cooler after i went to O'donnell 20%. Byrons is oilier than the leak in my t-bird.
also, I've run most of my engines way hotter than 280, and IMO as long as there's smoke, you're good. I abuse the hell out of my engines, and they last anywhere from 5 or 6 to 9 gallons.