Hows your CV boots after the lift? Any tears in them? I hear this is a common problem after a lift because of the angles the CV's now sit at. If you have a tear in the boots you could be getting some sand and grit inside the boot?

Just a thought as I'm not 100% sure what you've read, checked and eliminated at this point?

Is this a severe grinding or small but noticeable grind? Either way, I wouldn't drive it around too much replicating the noise as I'm sure it'll only get worse if you keep doing that.