dave i have pretty much the same mods as you.t6s k+n pods vf3s i also have my timing advanced 3 degrees and a noss head with 20cc domes on a 05 shee. i live in southern utah 5600 ft elevation but ride from about 4000 or 4500 up. sand hollow, coral pink and delta ,sand mountain or jerhico what ever you want to call it. never been to nevada. i run 280s and its jetted perfect just checked my plugs again tonight. i think your pretty close where your at do a plug chop and go from there i check mine anytime i do a mod just to be safe. im thinking your temps are going to be higher there so that might make a little difference