If you're not racing with an extremely built engine then your current Ignition system is more than adequate. As long as there's no "Weak Links" like voltage drop to the Coil or bad spark plug wires etc.. I used to advance the timing until point of Spark knock and then back it off just a bit. It always worked great for me with my Cuda 340. It seem that many people on this forum like using the Vacuum gauge better. I would Try that first. I'm not an expert but You should shoot for the Highest amount of vacuum at Idle in Drive.