All cylinders filling with water
just thinking here but you might want to pressure test the cooling system before you fire it up tomorrow after the heads are torqued down . do it with the spark plugs out so if its still leaking into the engine you know before it hydrolocks and causes expensive damage .
If you dont have a cooling system pressure tester last i checked they can be had at harbor freight for $35-$40 . much cheaper than destroyed engine parts imo .