440 boat engine vs. car engine?
If it helps, might be worth checking out. Some were Fresh Water Cooled which may have used antifreeze and some were Raw Water Cooled which comes directly from the water you're boating in.
Raw Water Owners can flush the engines with or without salt removers / rust inhibitors for winter layup or just drain them and let them rot. I use mine in fresh water only so I flush with tap water, drain and refill with marine antifreeze, drain and leave open to air.
If it helps, might be worth checking out. Some were Fresh Water Cooled which may have used antifreeze and some were Raw Water Cooled which comes directly from the water you're boating in.
Raw Water Owners can flush the engines with or without salt removers / rust inhibitors for winter layup or just drain them and let them rot. I use mine in fresh water only so I flush with tap water, drain and refill with marine antifreeze, drain and leave open to air.