I would like to interject this if I may, the Eddie Victor 340 is the best intake for SB Chrysler at this time according to Wilson Manifolds as well as PBR on this site. Now with that said, the Victor 340 requires a lot of work to make it good, so if you plan to just bolt on an intake to your engine as received from the manufacture the Eddie RPM would be better suited for this type of enthusiast.
According to J J at Wilson Manifolds the plenum on the Mopar M1 is to big for Street/Strip use and even for race only the Victor will make more power, but again needs a lot of work. Just wanted to throw this out there.
BTW, I did not speak to Wilson about the RPM Air Gap.