In addition to the BMW 2002 modifications mentioned on page 20 of the February 1976 issue of Roundel, I recently (July 1976) took the stock intake manifold off and ground the ports to correspond exactly to those in the cylinder head.
By putting heavy paper over the head and using the studs as the locating reference, it is quite easy to mark the openings with a soft piece of wood. Then the exact outlines can be marked with a soft piece of wood and cut out with an Exacto knife and transferred to the intake manifold (all of them were considerably smaller on my manifold).
Be sure to put rags deep into the intake ports and use a vacuum cleaner to get all the metal particles out after grinding with a cone shaped stone. Also, be careful not to get the ports on the manifold larger than those in the head since this would create an undesirable air dam.
The improvement in both performance and response is very dramatic, and is certainly worth the time and effort required.
Author: Thom E. Mitchell
Tech Ed. Note: He now has 10,000 miles on the car since the modification, and has had no side effects other than a slight worsening of gas mileage.