Dave and Tech - Sounds like some serious fun! The RPM manifold is actually only 5 dollars more at summit than the regular performer. I got the performer on ebay brand new for a great price though. Once it's running, if it needs some more hp, or torque I'll switch out to the rpm. I noticed they make two performance rpm manifolds for the 460 BBF. One is an air gap style which keeps the air fuel mixture cooler the other is the regular rpm setup. What type were you and Tech refering to? (Down the line it would be nice to switch to a polished manifold as well!)