You can test the theory easily. With the light on it, pull the timing up until the engine stops gaining idle RPM. It'll reach the point where it really starts to get a deep rough rumble at idle.....I always put my hand on the valve cover. You can really feel it when it gets there. Then, back off until that "extra" roughness goes away and look with the light where the timing is. Just play around with it until you pick up on that extra roughness. You'll spot it. It's not hard. It's a lot easier to spot with your hand on it. Of course, without limiting total, you'll not leave it there. This is just to see "how much" initial only the engine will like. I bet with stock compression and that big cam it'll be "around" 20.
