If you have that many hours on, you are good to go with the synthetic oil.

Extra 10W40 is a very light 40 weight, and makes a good spring/fall/winter choice in the mild south. Ester based oils have phenominal film strength, and I feel confident running a 10W40 it in all but the very hottest summer weather. I switch to 15W50, only when the daily high temps are consistently above 80 degrees. (You pray for 80 degree days around here sometimes.....I am riding in the low desert this weekend, and it is already in the high 80's/low 90's! We only ride in the morning and evening when it is that hot.)