I'm trying to start my big block that has been sitting for three years. I'm getting a good yellow spark out of my coil wire ( mallory). I,m not getting any spark out of the spark plug wires. I changed the cap and rotor and still the same results

Elmarco, yellow isn;t hot enough, it should be blue/white. Something's amiss.

Gene, I thought the spark was a little weak, so I changed the points. How many volts should I be getting at the positive side of the coil and at both ends of the balast?

The voltage you will measure at the coil and ballast will depend on whether or not the points are closed. If the points are open, you will read battery voltage everywhere. If the points are closed, you will read 12v on one side of the ballast, about 9v on the other, then 9v on the positive side of the coil, and 0v on the negative side.

HTH