SA-10 build

[RedRam23]

I need help figuring out my port Width, Length, and Height. 

I'm building two subwoofer boxes for my single cab ram. They're going to be wedge shaped.

The cubic ft per box is 1.25

Top Depth=6"

Bottom Depth=10

Height=15

Width=26

Going for 35 Hz

I'm running a Skar Audio RP-1500.1D

ANY HELP IS APPRECIATED! THANKS!