With the carb dialed in, we pulled the throttle lever and the big motor responded with a best of 630 hp at 5,600 rpm. The torque peak was 630 lb-ft at 4,700 rpm. So the change to a high-rise, single four-barrel intake picked up about 20 lb-ft and 20 hp over the dual-quad setup. That seemed about in line with our previous experiences with the Performer RPM intake manifold design, as it has always made really good power in this rpm range. A Mopar guy can't go wrong with either combination underhood. Both induction systems look great, and they both made excellent power for us.

BY THE NUMBERS
505ci Mopar Big-Block
Bore: 4.350-inch
Stroke: 4.250-inch
Displacement: 505.3 ci
Compression ratio: 12.5:1
Camshaft: COMP Cams XR292
hydraulic roller
Cam duration: 242/248 degrees
at .050-inch lift
Valve lift: .584/.579-inch
Rocker arms: RAS 1.60 ratio
Piston: Diamond Racing, custom
Block: '74 passenger car 440
Crankshaft: 440Source.com 4340 forged
Rods: Scat 6.800-inch Chevy H-beam
Cylinder head: Edelbrock Performer RPM
Intake valve diameter: 2.140-inch
Exhaust valve diameter: 1.810-inch
Intake manifold: Edelbrock CH-28
Carburetors: Edelbrock 1804 AVS (2)
Headers: Stahl 2x32 dyno headers
Distributor: MSD billet