New Best time for my 318!

I was running a Edlebrock RPM intake on my Demon that had a 360 in it.I was spraying 125 shot of NOS on it. It would pick 5 tenths in the 1/8. When I put a single plane intake on it the next weekend it picked up 7 tenths. I was shocked that a single plane made that much difference when using NOS. It ran about the same without NOS with both intakes. It was a Holley Strip Dominator single plane intake.