I brought a 4 port intake gasket home, since these are a very good match to my current ports, and did some measuring of areas.  The port holes are elongated circles, and were calculated that way. 

Secondary- 1.5” tall x 1.125” wide.  This gives a 1.125” circle equal to .99 sq in, and a rectangular area of .375” x 1.25” equaling .42 sq in.   Total area for one secondary port is 1.41 sq in.  This would equal a round tube with the a 1.34” ID.

Primary- 1.5625 tall x .75” wide.  This gives a .75” circle equal to .44 sq in, and a rectangular area of  .8125” x .75” equal to .61 sq in.  Total area for one primary is 1.05 sq in.  .  This would equal a round tube with the a 1.16” ID.

The total area for a combined primary and secondary is 2.46 sq in.  My current 1.625” ID tubing only has an area of 2.07 sq in, meaning it’s 16% smaller than the runners in the side of the housing.  A combined runner would require at least a 1.77” ID tube to feed the primary and secondary of one rotor. 

I'm looking into making a "simple" style intake like Tracy, and Bruce are doing, though I haven't committed to any particular design.  

Cheers,

Rusty