winterizing 5.7L GI (2008)

[Camp]

Can I add antifreeze through the engine flush tube, or do I have to suck it in from the drive with muffs. This is a raw water cooled engine, not closed system

[wake my day]

Still a scary issue if the thermostat does not open when you are sucking anti freeze into your engine. If the cold water and antifreeze closes your thermostat, you will have raw water left in the block and experience a cracked block. Are you draining the block first?