Yes that is what i'm trying to say. I had 18 at idle and at 1500 rpm. At 2000 it was 26 degrees. So some time between 1500 and 2000 rpm is when it started to advance. 2500 rpm 28 degrees, 3000 rpm 35 degrees.

I should add that these two light springs didn't look exactly the same. But they came out of stock 81 and 85 truck small block distributors.