Top Street Performance Pro Series Ready to Run distributors are the best upgrade for any old ignition system. The CNC machined body construction, oversized hardened steel shaft, top sealed ball bearing and lower sintered bushing provide the strength and durability for years of operation. An integrated high performance circuit board provides smooth firing to 10,000 RPM and work best with a Top Street Performance Power Coil (JM6930). Features continue with adjustable vacuum advance, hardened steel gear, additional springs and bushing for fine tuning of mechanical advance.