This is a Chevrolet intake manifold PN 3917610 used on the 67-68 Z28 302 engine. I purchased this ultra nice manifold, and as you can see it is nearly perfect. Obviously this manifold has not seen many miles. 

This is a good shot showing factory casting surface. Glass beading removes some of the "flaws" and ruins the originality of the manifold

Here is a upside down shot showing the heat shield.

Since the engine was painted with the intake manifold installed, you can see remnants of Chevy Orange paint on the corners...

Shot of orange.. And the Winters foundry "snowflake" logo.

Orange over spray

It appears there are three locations for date coding on the 610 intake. Click here for location info.