Carter / Edelbrock Carbs- step-up springs

I was recently doing some carb tuning, and i seemed to notice a discrepency in the color code of the step-up springs. When i went from pink to plain springs to fatten up my transition, it made the leaner. This made me want to test the springs that i had on hand, here's what i found out...
...spring length installed w/ piston "up"- 1.125" (rich position)
...spring length installed w/ piston "down"- .843" (lean position)

I used a postal scale to read the spring loads in "grams" at the two different installed heights. The 1st number is the spring load in the "up" position, 2nd number is the spring load in the "down" position. Here's what i found...
...blue 3" springs- 10g/160g
...yellow 4" springs- 48g/170g
...OEM Carter/Edelbrock springs- 95g/208g
...orange 5" springs- 105g/215g
...pink 7" springs- 200g/320g
...plain 8" springs- 130g/320g

My wideband confirmed my findings. Maybe i'm colorblind on the pink/plain?

 

I know this is a really old post but I had to finally make an account when I ran across this post by weedburner because I had preformed the same test on the edelbrock step up springs and had very similar results. My only delta was the plain was 300g in the rich position.

I needed more spring than the plain and the pinks just look like they would take more vacuum to pull down. I have yet to road test this but it was just cool to find someone else tested these out.

 

A drive test confirmed to me that the pink springs are higher vacuum than the pain ones. It took less pedal effort to get the circuit to transition to power with the pink springs.