Lean idle. Rich cruise.

With a cam that big you should probably just tune it by ear at idle while also watching the vacuum gauge. Play with the idle mixture screws and the initial timing to get the best quality idle with the highest vacuum reading. If the wide band tells you that it is 15:1 then you know it is lying to you. With a big cam the engine will need something around 13.5 at idle but the wide band might read 15 or 16 due to air sucked into the exhaust during overlap.