Performer RPM Vortec ManifoldThis single four-barrel intake is designed for the street rod, marine and engine swap market utilizing 262-400 c.i.d. Chevy V8s with 1996 and later Vortec (L31) cast iron or the Edelbrock E-Tec aluminum heads. An external water bypass boss is machined into the front of the water crossover for use on 1996 and later Vortec production engines. Manifold accepts square-bore carbs only. For street and marine engines operating from idle-5500 rpm. Will not fit under stock Corvette hood.