My car is a L6. It has what I believe is an aftermarket manifold. It has 2 ports for a true dual exhaust. Has anyone seen anything like this before? Thanks.

It may be a Clifford Performance piece. Look at www.cliffordperformance.com (http://www.cliffordperformance.com)

Chevy did make a dual outlet exhaust manifold for the 250 L6 from 1980 - 1984 for pickups (and I guess vans) for under 6000 lb. GVW.

That would make sense, as the engine in the car is a 250 out of something later. Thanks.