winterizing a motor

We just recently bought a 1977 Exective by Invader with a 302 ford motor. Can anyone tell us how much antifreeze it will take to winterize this motor? We have read your posts and find them very interesting. The you Invader

[Col]

Has your engine got a heat exchanger? a 30% mix should be about right.You should have some left out of a 5 ltr can