is that a good thing to do? i am just curious. my intake manifold has some pretty dinkey seccondarys on it. and the intake ports on the plates are alot bigger. would that be something that i should do? mathc the ports?

 

from what i've heard in the 1st gen section, no. however it is popular to get a 79 intake manifold as they were larger and flowed better, before the pollution ***** were starting to get into full affect.

 

Jeremy is correct on this one. The problem with port matching that manifold to the engine is that most of the matching has to be done upwards with a little down as well. When you match the upper side you have made the short turn radius of the runners smaller. This is bad for airflow. The more gradual the turns the better. By moving this top edge up you are going to increase intake turbulence. This in turn decreases flow even though the runner opening is bigger. It will kill the air velocity. Also the large port opening in the engine as opposed to the runners is ideal in preventing version. Since there is a lip going back into the manifold, it effectively stops any negatively traveling pressure waves from going back up the manifold. If you have the air cleaner assembly off and run the engine, hit the throttle hard and look to see which runners you get the smoke back out of. It's not the primaries! This is also why it isn't a good reason to port match any other manifolds to the engine. All of my engines have smaller runner openings than engine runners.

 

i'd also like to add that the manifolds are rough on the intake runners to promote automization, meaning even if port matching helped that you would need to mimick this or see no gains as well.