Pole Position has a great big transformer mounted on what's called the metal "power chassis" down in the bottom floor of the cabinet. This is where the game power cord connected to and where the fluorescent lights, power on-off switch, and safety interlock switches connect. All the fuses are located there, too. The big transfomer has multiple windings in it. One of those windings is the monitor isolation transformer section. Another internal winding powers the coin door 6 volt lights and a couple more windings provided low voltage ac to the two power supply circuit boards that originally powered the Pole Position game boards. If this "power chassis" is still there, great, you're in good shape. Get the game schematics and you'll be ready to power your monitor.
Be advised that some game operators may have modified the wiring harness to remove the original power supply boards and run the game boards from a modern switching regulator power supply instead (it's a big improvement).