Single vs Dual Plane, big difference?

It is VERY combo dependent. I have run both the RPM Air-gap dual plane, and the Victor single plane on my 410. The Victor is quicker on my combo, but it took quite a bit of tuning to get it that way. I have been 10.89 @ 122 with the Air-gap, and 10.79 @ 123 with the Victor (doing an apples to apples comparison, both on pump gas). I now run on e85, and with the Victor have been 10.54 @ 125.

The Air-gap is the best all-around intake I know of for the small block Mopars....In my opinion.