The RV guys love them , I tried one out for grins on a 10:1 440 and didn't think it was much if any better than a stocker, definately not on par with the Weiand Action plus or the CH4b which were really the only other dual planes at the time (Pre RPM days).

I think I'd pass for what you have in mind, if you want to look stock and flow mad air I'd look at the Indy 440-2d...a little radius work on #4 and #7 is all they need to get them all to flow about 315 cfm at the 906 size port.