The Project Pad

Who runs what spring in their Tial Q? My engine idles at ~16 in/ng vac, but frequently operates at more vac than that when commuting. I'd like to avoid the valve being open during cruise but still get good response. Suggestions

My car idles with 15in/mg, which according to the spring chart is the white spring(-8). However, I'm using the black spring(-6) for the best response up here at 9k' alt. From what I've read, the chart is a guideline or starting point but just use the weakest spring possible without getting any valve creep.