6.1 cam swap. Big deal?

Should be pretty straightfoward for you then. Pulling the cover makes a bit of a mess and the more coolant you can get out first the better. Since the oil pan sticks under the front cover, any coolant you don't get out of the water pump passages will dump right into the pan. Changing the oil after is a good idea, but you know there will always be a little bit of coolant left. Probably nothing to worry about, but annoying nonetheless.