Using 79 intake manifold on later motor
 

I run an IT7 car, and I've heard that the 79 intake w/o the shutter valve makes more power.

I have a 79 intake that I want to use on an 81 motor, but there is an additional port in the motor below the two center intake ports that is not covered by the 79 intake.

Anybody know what this port is and how to block it off?

Thanks.

Its a port for the air pump. Make a block off plate with a piece of aluminum L angle. Screw it to the bottom of the manifold so it blocks the port when installed.

If you ever have the engine apart you can block the actual passages in the rotor housings with some aluminum dowels.