Since distributors have manufacturing tolerance of up to 4 degrees, you want to make sure your distributor is adjusted to the optimum HP and fuel economy.
In other words, adjusting to stock timing settings you may be losing HP.
Quote:
Total Advance measured at 4800 RPM
A12: 32 degrees total
A14: 34 degrees total
This is the high side of the factory settings.
For 1972 and older engines, use this template to mark rim of pulley with paint at 28, 32, and 36 degrees
template
For 1972-up engines, securely fasten this card to timing cover:
Timing card 
Connect timing light and rev engine until timing stops advancing (should be somewhere before 4800 RPM). Check timing at this maximum advance. Note which Pulley mark lines up. Turn engine off, rotate distributor appropriate number of degrees, then repeat full advance check.

Finish by verifying engine does not knock/ping via Ear Test:
1. Disconnect and plug vacuum advance line so it will not advance the timing
2. Set initial timing to 2 degrees advanced from stock setting (9 or 7 BTDC)
3. Road test car at full throttle (up to full advance RPM). Use a hill to load the engine, and second gear to keep road speeds low.
* If it pings at full throttle, set distributor back 2 degrees degree and repeat test
* If it does not ping, advance 2 degrees and repeat test
4. Reconnect vacuum advance line, and test for pinging at light throttle. Retard timing if needed (which would indicate a need to customize the vacuum advance curve)
INITIAL TIMING
After setting the total timing, turn engine to 20 BTDC, then rotate engine until points open (or EI teeth align). This is your new static setting.