Total Mechanical Advance on a 72 Q Code

Check out this article on Ford Muscle:

http://www.fordmuscle.com/archives/2000/03/timing/

But the synopsis is the following:

..."The rule of thumb is that the higher the compression ratio, the less total timing it can handle before detonation, and also the higher octane rating it needs to control detonation. Low octane fuels ignite faster, thus require less timing advance. Conversely high octane fuel can handle slightly more advance. Dyno testing has shown that most small block Fords with 9:1 to 9.5:1 compression make peak HP with 38-42 degrees total advance. Engines with 9.5:1 - 10.5:1 run best with 35-38 degrees total, and above 11:1, should not go higher than 35 deg. total. When using power adders such as nitrous, super or turbo chargers, the timing should be advanced accordingly..."

4V Clevelands like LOTS of initial advance and a very quick timing curve. I recommend something like 12-15 initial (if your starter can handle it) and 35-40 total. The advance should be all in by 3000 rpm.