Dual quads versus big hammer!!!...

So...I think you should go out and get some vacuum reading at a cruise. Then, set your springs to open a few numbers below what cruise vacuum is. For example, if you cruise vacuum is 15 inches, set your springs to open at say...11 inches and see what happens.

If your idle vacuum is say...only 9 inches, you can test to see if the metering rods being up at idle makes a difference (I don't think it will because the idle feed system is very similar to a Holley and the Holley guys have been getting it wrong for decades) or if it doesn't matter. I don't think it will matter.

You can tell by verifying your A/F ratio at idle with say...a spring that pulls the metering rods up a 6 inches of vacuum and compare that to the A/F ratio at idle with the 11 inch springs in it.

If I'm correct, the A/F ratio will be the same at idle with either spring in it it, and the higher spring number (pulling the metering rods out of the jets sooner) will help clean up the lean spot on cruise tip in.