Whats the timing and any KR at WOT?
10.5 is not terrible, mail order tunes tend to run rich because that better than running lean.
I run anywhere from 8-9.5 AFR, because my tuned is ****ed, and its ran okay LOL, and yes I will get it fixed.
If you are not showing any KR and everything seems fine, a pulley drop may be okay, you'll have to watch and see how the car takes it.