Distilled or Regular Water

Distilled or at least "grocery store" demineralized water never hurts. But it depends on "your area." I can still remember the first week I had my car in San Diego, wondered why everybody was wiping down their cars after the car wash. I soon found out!!! You could not see through the windshield!!!!

Friend of mine down there, now gone, had bought a brand new 70 Chev 3/4T 4x4, and used distilled water and 50-50 anti freeze exclusively. The inside of that system (with a head and cam change) looked like brand new in there. Life expectancy on radiators on tap water in San Diego is not very long.