I run two ballcheck valves, one for each hose, during warm up during the summer I'll leave them open now and then, out with the old in with the new, I run approx. a 30%-70% antifreeze to water with a pint of Prestone waterpump lube to make up for the missing anti corrosion package with the -20% less antifreeze, I have no problems,runs cooler without adding water wetter, it also helps to add waterpump lube to a 50-50 mix, its a water soluable oil.