I used that 5 gallon jug kit from amazon for my 5.0mpi's. Am worried sick because of reading all the horror stories. I ran 5 gallons of -75° through them only after brought up to temp and didn't drain anything out afterwards. So i ending up making a trip out to the cold indoor storage place where my boat is once it got below zero for about a week. I then removed the 4 blue plugs on each motor and antifreeze came out. I should be good right?