How can you tell difference from d-port, oval, square port heads?

I don't know which numbers to look at on the outside of the head. The ones I have seen are cast into the head under the valve cover.

Some where I have a link of which numbers are which heads. I'll look for it.

Here it is.
http://www.mortec.com/bbc.htm

D port head most people are talking about the exhaust port shape. Peanut ports are very small intake ports about the size of a golf ball. Oval port are also talking about the intake ports, they are about the size of a 1 1/4 hose. Finally the square port or rectangular port is large from top to bottom of the intake runner. Its name is its shape.

John S.

The first picture is a standard oval port, the second is a rectangular or square port and the peanut isnt shown but is another 1/3 smaller than the oval port.

Hope this helps.

Thanks for the lesson, good info to know.