I'm porting heads for the first time and when I scribed them for gasket matching I noticed that the outer runners are way smaller than the middle ones.

Does that mean different runners have different flows in stock form?

 

If you measure the flows of all the runners on a flow bench, they should be pretty close to each other, but they won't be the same. As far as the outer runners being physically smaller, it's most likely an attempt to keep the velocity high.

 

so when gasket matching the runners do I want to actually match the gaskets if in stock form they are very close as far as flow goes? If I port more on one runner than I do others won't I get different flows?

 

As long as you're only gasket matching you should be ok. Just be careful if you go deeper into the runner.

 

 

To give you a pic, as an extention of what OldSStroker is referring to, scrol down aways, and check the pic, in link below, displaying the intake assembled to the heads. Ya, it's an LT4. but the intention is to show the relationship of head port to intake tract. To that end, it is extemely similar. The intent is to put in a visual sense, the intake is an extention of the intake port in the head. What the porter is striving to accomplish, is to have a uniform cross section area, in any given section of the port.

http://pws.chartermi.net/~steveher37/LT4/lt4.html

Edit: BTW, B4 anyone scrutinizes the LT4 manifold port to head port alignment, and attempts to make an issue, the pic referred to above, is (I firmly believe) an LT4 engineer's rendition of how the LT4 manifold port was intended to align, in respect to the opening/port in the head. It is not, what we, the consumer ended up purchasing. A 'bean counter' took care of that.