I spent days dyno testing intake manifolds on a 440/496 with a 249/255, .585/.585 solid roller cam and RPM heads that flowed 310 cfm @ .600". A mildly ported Edelbrock Performer RPM intake consistently made 30-40 lb-ft more in the lower rpm ranges than any single plane intake we tried. In addition, to 6,000rpm, the dual plane RPM never lost more than 5 HP to any of the single plane intakes. Above 6,000 rpm the Victor made 15-20 more horsepower if I added a 2" 4 into 1 spacer.
Intake manifold with a carburetor on the street? Of the ones I've tested......Edelbrock Performer RPM dual plane for me.
