Brice, thanks for the update, nice to hear that you were able to get out and do some exploring, bummer about the boys turning you around and giving you a hard time.

CrazyCarl and I went through there during the second week of July and were able to make to Litang. Litang is about as far west as anyone is going to get for the time being. You need to start in Yunnan and hit G214 or S226 North to Zhongdian (Shangrila). From there you can take S217 North to Litang, but you will probably be stopped at least once. Be sure to make it very clear that you are going to east to Chengdu and have no intention of going west on G318. When you reach the intersection of S217-G318 in Litang, some nice people will greet you and direct you east. If you need to stay overnight, they will probably tolerate it, but let's just say that tourism isn't exactly booming in Litang.

Cheers!
ChinaV