Carburetors calibrated for elevations close to sea level also run RICH at Denver's altitude, since a carb mixes fuel and air by weight, not volume and the air at 5K+ feet isn't as dense as it is at lower elevations. Running a main jet a step or two leaner is probably a good idea, but looking for different jets for the Weber is probably going to be like finding a chicken with lips.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!