P/S belt squeal

Have been chasing a squeal for some time now and narrowed it to the P/S belt. The belt was very tight so that was not the issue. Was using a Dayco 15465 so thought I'd try a Gates so got a XL 7465. It squeals more than the Dayco one did. I tried gently sanding the pulleys which made no difference. The belt rides just a bit high on the P/S pump and is below level on both the water pump and crank pulleys. I don't know where these pulleys came from and are likely not original.

Any thoughts on how to stop the screaming??