Nicky pointed to a Vortec head on a rotating stand. For illustration only, he had overlaid the intake ports with a stock gasket from a conventional small-block Chevy to physically see the raised ...

The stock intake flowed 246 cfm at 0.550 lift, and the exhaust flowed 162 cfm at 0.450 lift. ... The Vortec intake manifold is constructed in two separate pieces.

GM Vortec heads are arguably the best-flowing Gen I factory, stock-production, cast-iron, head ever offered. Edelbrock offers a special Air-Gap Vortec intake for them (PN 7516).

The marine port-injection intake manifold accepts the stock Vortec throttle body and smog equipment. The throttle body sits in the same place as the stock truck L31 intake, so most aftermarket ...