For the ultimate in street performance, what else would you choose besides a dual-plane intake, Indy style? This manifold (PN 440-20) offers better throttle response than a similarly-sized single plane, but with the amply-sized runners, there are few single planes that actually displace more air for Chrysler B/RB engines. The efficiency of the dual-plane design assists to make the 542 a clean burning engine, even if it is a thirsty one. The throttle response is staggering and the wide power band from 1,500 to 6,000 rpm makes this the perfect manifold for big-inch Wedge engines. If you are looking for a universal B/RB manifold, this is it! It fits 906 castings as well!