The lack of belt dust tells me you are not slipping that much. If there is a lot of black dust which I just can't see in the pic, then you do have a belt slip problem.
The problem I had with mine I pointed out with arrows above. That small black bracket needs to be moved as far back as you can. It kind of looks like the inside of the belt may be making contact there.
Also, I used the BGG 8-rib kit up to 18-20psi and it worked good, so if you determine you do have belt slip, that 8 rib kit will fix it. Also use the Gates K081223HD belt if you go the 8 rib route. If you have a larger a/c delete pulley or a larger balancer (10% over) you may need the K081265HD belt.