The Performer Manifolds are dual-plane, low-rise intake manifolds with a 180 degree firing order and patented runner design. This combination boosts torque over a wide RPM range, from off-idle all the way up to 5,500 RPM. The Performers are ideal for passenger cars, boats, tow vehicles and RV's. They accept late-model choke, water neck, alternator, air conditioning brackets and have provisions for oil filler tube.