Antifreeze

I need two know what mix and how much antifreeze to put in my caprice. Its a 5.0L 305

50-50 is ok. You can go as high as 70-30.

Of all the times I flushed/filled mine, I bought two gallons, installed 'em right after a flush, and poured the extra into the overflow tank.

another good rule is once you pierce the seal on the gallon jug, mix it 50-50 so it's ready to use. that way if the bottle is sealed, you know it's full strength, and if it's opened, you know it's mixed, and you don't accidentally re-dilute some and cause a winter freeze up or summer boil over. If you are looking for you cooling system capacity, it should be somewhere between 11 and 14 quarts total, depending on if its a heavy duty cooling system.