Classic/Antique Car Repair: oil changes, ford v8, changing oil

Question
I have 4 collector cars (1936,2-1970, 1972 ford v8's) all driven occasionally but a total of less than 1,000 miles a year. All covered and stored in a warm garage. How often should I be changing oil?

Answer
In my opinion once a year would be more than sufficient to protect these cars. I am more concerned with the state of the gasoline in storage than the engine oil. I would make sure to use a product like STA-BIL in the fuel. It claims to keep gasoline fresh for up to a year. I would use the marine formula.