I purchased an Edelbrock intake manifold baseplate that was installed at the same time I replaced my old engine with a 355.  The pictures were taken after I ported out the manifold, smoothing all of the runner inside surfaces, and gasket-matching the openings from the runners and to the cylinder heads.

Pictures

Left side of manifold. The 2 center bolt holes on each side have 2 different angles reamed out to accommodate both older (pre-'87) and newer-style intake manifolds. The manifold also has the EGR ports in both F-body and Corvette positions.  The runner openings have been ported out to 45mm in diameter (manifold was originally 42mm) and the passages further ported and cleaned up the whole way through.

Right side of manifold. The supplied block-off plate is attached to the Corvette EGR port next to the
distributor opening, along with a home-made block-off plate on top.  The coolant hole between the  block-off plate on the left and the distributor hold-down bolt hole is plugged with a 1/8" NPT plug.

Underside of manifold. Notice the injector ports in the runners. The large pipe plugs seal up holes that were cast in the manifold so that the idle air openings could be drilled into the bottom of each runner at the factory. The ports going to the cylinder heads originally measured 1.92" X 1.15" but were gasket-matched to the FelPro 1205 intake gasket at 2.09" X 1.28" after this picture was taken.  I bought a new intake valley pan from GM, part number 14087401, for about $7.

Last update: March 20, 2004