Delco Distributor Advance

Or you do it on a distributor machine. Honestly if ignition point distributors are going to be a regular thing for you, a distributor machine is worthwhile. I hate leaning way over the fender to reach distributors that are way at the back of the engine for things like point changes. It's easier just to pull them out and plop them on the machine. 

Factory timing curves are conservative because they are designed to work under all operating conditions, whether it's Arizona in July or Minnesota in January, without detonation. They are designed so the vehicle owner can set their engine to that specification and forget about it. Most factory-spec timing curves leave about 5% more torque output on the table during good conditions (Minnesota), but that margin narrows under bad conditions (Arizona). 

You can advance your timing under good conditions (high altitude, humid, cold, high octane gas) if you want, and get about 5% more torque. But you would have to retard the timing back down again when the conditions got worse to avoid melting your pistons right out of your engine block.

Have you ever noticed how many 1967 and up AMC V8's have broken piston ring lands? It's not a manufacturer defect. It's because people crank up their timing thinking they are so gosh-darn smart. Detonation can happen without you ever hearing it and it's a cumulative thing that adds up over time. 

Moreover, the timing curve is designed to match how the engine's timing needs change over its operating RPM range, which is determined by the engine's mechanical design and configuration (cam, combustion chamber, etc.) rather than the operating conditions (humidity, octane, etc.). Adjusting the timing for operating conditions should be done by adjusting the BASE timing setting rather than the advance curve.