Edelbrock part #29025 Victor Jr. 454-R EFI intake manifold is designed for competition 396-502 big-block Chevy engines with rectangular-port cylinder heads. It features extended runner dividers, smaller plenum chambers and unique runner design for better 60 foot times and max power from 3500 to 7500 rpm. These intake manifolds are especially suited to 502 c.i.d. and smaller competition engines. The Edelbrock Victor Jr. 454-R EFI intake manifold will fit Edelbrock Victor race cylinder heads #77609 and Victor 24 degree #77409, #77459, #77429, #77479 and #77489.