The distributor has the medium blue springs that came with the unit. According to them 22-24 degrees of crank advance is all in by around 3300. I have not tested that.
Try one heavy and one medium as a test. What cam? How much duration @50? Initial timing? That's a lot of crank degrees, So at 36-38 total for iron heads you would be at 12-16 initial. I would think 18-20 initial on a street engine.
