After I've had my customers test them and 6 months later I finally took my pump off to fix the rounded off bolt so I could get my afc top off to fix the afc lever/slide pin issue.
My AFC spring is well......................stiff.
With a modified stage 1 Denny Pin (not my first choice for sure) and the starwheel the right side up and about 3/4 of the way up, I can only hit 32 psi and 1050 degrees...... boy howdy is she a good running truck that way, especially with the 3800 spring.
Point being, I can achieve full boost with it bottomed out but the spring is stiff enough to hold back well over 40psi from my testing.
Now for those who don't ahve that much boost, this spring is designed in a way where we can shorten it as need be.