Chart for various stock advance curves
Here's a governor slot length to degree chart. Includes both crank and distributor (cam) degrees. I needed 10 degrees, so I had to kinda shoot from the hip. I used a protractor and measured 5 degrees at the distributor and welded and filed the slots accordingly.
Cam Crank Slot length
6° 12° 0.340"
7° 14° 0.357"
8° 16° 0.375"
9° 18° 0.390"
10° 20° 0.405"
11° 22° 0.420"
12° 24° 0.435"
13° 26° 0.447"
14° 28° 0.460"
15° 30° 0.475"
16° 32° 0.490"
17° 34° 0.505"
18° 36° 0.520"