Re: 502 Timing
With vacuum advance disconnected, set the total at 36°. Then if you let it idle, you'll see that its at or near 16°. Be sure the idle speed is slow enough that you're not starting the mechanical curve (around 800-900 should work) "Most" distributors have about 20° of mechanical advance in them, some a little more, some a little less. You adjust the rpm level with springs and bring the total in earlier or later. You can play with weights if needed to get the 20° you'll need. You may also find that you need to limit the vacuum advance depending on your application. There are also adjustable advances and limit cams for this purpose.