Those speakers are 8 ohms, so connect them to the 8-ohm terminals.
McIntosh MC611 (terminal 2, 4, or 8 ohms)to B&W 800d3's
I would like to know when connecting from B&W 800d3 speakers to McIntosh MC611 mono-blocks which (2, 4, or 8 ohms terminal) should I use for best results?