CHEV 350 WEIAND ACTION PLUS VORTEC INTAKE MANIFOLD # WEI8121CHEVROLET SMALL BLOCK WEIAND ACTION PLUS VORTEC INTAKE MANIFOLD. # WEI8121 Dyno proven performance from Weiand. Weiand Action+Plus intake manifolds are designed for use as stock replacements, with improved power and torque characteristics. They're 180 degree, dual plane types, with a carburetor flange that'll accept either stock or aftermarket performance carburetors. Their effective rpm range runs from idle to 6,000 rpm. With their high flow runner